diff --git a/FineCodeCoverageTests/FileLineCoverage_Tests.cs b/FineCodeCoverageTests/FileLineCoverage_Tests.cs
index 3cc6ea46..03c1e8c3 100644
--- a/FineCodeCoverageTests/FileLineCoverage_Tests.cs
+++ b/FineCodeCoverageTests/FileLineCoverage_Tests.cs
@@ -16,15 +16,16 @@ private static ILine CreateLine(int lineNumber, CoverageType coverageType = Cove
             return mockLine.Object;
         }
 
-        [TestCaseSource(nameof(Cases))]
-        public void GetLines_Test(IEnumerable<int> lineNumbers, int startLineNumber, int endLineNumber, IEnumerable<int> expectedLineNumbers)
+        [Test]
+        public void Should_Return_Distinct_Sorted_Lines()
         {
             var fileLineCoverage = new FileLineCoverage();
-            fileLineCoverage.Add("fp", lineNumbers.Select((n => CreateLine(n))));
+            fileLineCoverage.Add("file1", new[] { CreateLine(2), CreateLine(1), CreateLine(3),CreateLine(1) });
             fileLineCoverage.Sort();
 
-            var lines = fileLineCoverage.GetLines("fp", startLineNumber, endLineNumber);
-            Assert.That(lines.Select(l => l.Number), Is.EqualTo(expectedLineNumbers));
+            var lines = fileLineCoverage.GetLines("file1");
+            
+            Assert.That(lines.Select(l => l.Number), Is.EqualTo(new int[] { 1,2,3}));
         }
 
         [Test]
@@ -32,7 +33,7 @@ public void Should_Get_Empty_Lines_For_File_Not_In_Report()
         {
             var fileLineCoverage = new FileLineCoverage();
 
-            var lines = fileLineCoverage.GetLines("", 1, 2);
+            var lines = fileLineCoverage.GetLines("");
 
             Assert.That(lines, Is.Empty);
         }
@@ -50,6 +51,7 @@ public void Should_Rename_When_FileName_Changes()
             var fileLineCoverage = new FileLineCoverage();
             var lines = new[] { CreateLine(1), CreateLine(2) };
             fileLineCoverage.Add("old", lines);
+            fileLineCoverage.Sort();
             AssertLines("old");
             
             fileLineCoverage.UpdateRenamed("old", "new");
@@ -62,18 +64,5 @@ void AssertLines(string fileName)
                 Assert.That(allLines, Is.EqualTo(lines));
             }
         }
-
-        static readonly object[] Cases =
-        {
-            new object[] { new int[] { 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20}, 19, 20, new int[]{ 19,20} },
-            new object[] { new int[] { 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20}, 12, 13, new int[]{ 12,13} },
-            new object[] { new int[] { 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20}, 6, 7, new int[]{ 6,7} },
-            new object[] {Enumerable.Empty<int>(), 0, 4,Enumerable.Empty<int>() },
-            new object[] { new int[] { 3,2,1}, 0, 4, new int[]{ 1,2,3} },
-            new object[] { new int[] { 3,2,1}, 0, 3, new int[]{ 1,2,3} },
-            new object[] { new int[] { 3,2,1}, 1, 2, new int[]{ 1,2} },
-            new object[] { new int[] { 3,2,1}, 2, 2, new int[]{ 2} },
-            new object[] { new int[] { 3,2,1}, 4, 5, Enumerable.Empty<int>() }
-        };
     }
 }
diff --git a/SharedProject/Core/Cobertura/FileLineCoverage.cs b/SharedProject/Core/Cobertura/FileLineCoverage.cs
index 822b1c97..5a828332 100644
--- a/SharedProject/Core/Cobertura/FileLineCoverage.cs
+++ b/SharedProject/Core/Cobertura/FileLineCoverage.cs
@@ -1,21 +1,54 @@
-using FineCodeCoverage.Core.Utilities;
-using FineCodeCoverage.Impl;
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 
 namespace FineCodeCoverage.Engine.Model
 {
+
+    internal class UniqueCoverageLines : HashSet<ILine>
+    {
+        public UniqueCoverageLines() : base(new LineComparer())
+        {
+        }
+
+        public void AddRange(IEnumerable<ILine> lines)
+        {
+            foreach (var line in lines)
+                Add(line);
+        }
+
+        private IEnumerable<ILine> sortedLines;
+        public IEnumerable<ILine> SortedLines => sortedLines;
+
+        public void Sort()
+        {
+            sortedLines = this.OrderBy(l => l.Number).ToList();
+        }
+
+        class LineComparer : IEqualityComparer<ILine>
+        {
+            public bool Equals(ILine x, ILine y)
+            {
+                return x.Number == y.Number;
+            }
+
+            public int GetHashCode(ILine obj)
+            {
+                return obj.Number;
+            }
+        }
+    }
+
     // FileLineCoverage maps from a filename to the list of lines in the file
     internal class FileLineCoverage : IFileLineCoverage
     {
-        private readonly Dictionary<string, List<ILine>> m_coverageLines = new Dictionary<string, List<ILine>>(StringComparer.OrdinalIgnoreCase);
+        private readonly Dictionary<string, UniqueCoverageLines> m_coverageLines = new Dictionary<string, UniqueCoverageLines>(StringComparer.OrdinalIgnoreCase);
 
         public void Add(string filename, IEnumerable<ILine> lines)
         {
             if (!m_coverageLines.TryGetValue(filename, out var fileCoverageLines))
             {
-                fileCoverageLines = new List<ILine>();
+                fileCoverageLines = new UniqueCoverageLines();
                 m_coverageLines.Add(filename, fileCoverageLines);
             }
 
@@ -25,30 +58,18 @@ public void Add(string filename, IEnumerable<ILine> lines)
         public void Sort()
         {
             foreach (var lines in m_coverageLines.Values)
-                lines.Sort((a, b) => a.Number - b.Number);
+                lines.Sort();
         }
 
         public IEnumerable<ILine> GetLines(string filePath)
         {
             if (!m_coverageLines.TryGetValue(filePath, out var lines))
             {
-                lines = Enumerable.Empty<ILine>().ToList();
+                return Enumerable.Empty<ILine>().ToList();
             }
-            return lines;
+            return lines.SortedLines;
                 
         }
-        public IEnumerable<ILine> GetLines(string filePath, int startLineNumber, int endLineNumber)
-        {
-            if (!m_coverageLines.TryGetValue(filePath, out var lines))
-                yield break;
-
-            int first = lines.LowerBound(line => startLineNumber - line.Number);
-            if (first != -1)
-            {
-                for (int it = first; it < lines.Count && lines[it].Number <= endLineNumber; ++it)
-                    yield return lines[it];
-            }
-        }
 
         public void UpdateRenamed(string oldFilePath, string newFilePath)
         {
diff --git a/SharedProject/Core/Cobertura/IFileLineCoverage.cs b/SharedProject/Core/Cobertura/IFileLineCoverage.cs
index b9eafc7d..4e9e86b0 100644
--- a/SharedProject/Core/Cobertura/IFileLineCoverage.cs
+++ b/SharedProject/Core/Cobertura/IFileLineCoverage.cs
@@ -5,7 +5,6 @@ namespace FineCodeCoverage.Engine.Model
     internal interface IFileLineCoverage
     {
         void Add(string filename, IEnumerable<ILine> line);
-        IEnumerable<ILine> GetLines(string filePath, int startLineNumber, int endLineNumber);
         IEnumerable<ILine> GetLines(string filePath);
         void Sort();
         void UpdateRenamed(string oldFile, string newFile);