Add tests for Convert package

src/SparseTransform.Tests/Library/Convert/DotWriterTests.cs

+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Antlr4.Runtime;
+using System.Xml.Linq;
+using NUnit.Framework;
+using SparseTransform.DataStructures;
+using SparseTransform.Convert;
+
+
+namespace SparseTransform.Tests.Library.Convert
+{
+    public class DotWriterTests
+    {
+  
+        
+ 
+        [Test]
+        public void writerTestBipartite()
+        {
+            DotWriter writer = new DotWriter();
+
+            BipartiteGraph graph = new BipartiteGraph();
+            graph.AddEdge(1, 1);
+            graph.AddEdge(1, 2);
+            graph.AddEdge(1, 5);
+            graph.AddEdge(2, 3);
+            graph.AddEdge(3, 2);
+            graph.AddEdge(3, 3);
+            graph.AddEdge(3, 4);
+            graph.AddEdge(4, 1);
+            graph.AddEdge(5, 4);
+            graph.AddEdge(5, 5);
+
+            string[] lines = writer.Write(graph).Split(
+            new string[] { "\r\n", "\r", "\n" },
+            StringSplitOptions.None
+            );
+
+            Assert.That(lines[2], Is.EqualTo("\tc_1  [shape=circle, style=filled]"));
+            Assert.That(lines[4], Is.EqualTo("\tc_3  [shape=circle, style=filled]"));
+            Assert.That(lines[5], Is.EqualTo("\tc_4  [shape=circle, style=filled]"));
+            Assert.That(lines[13], Is.EqualTo("\tc_2 -- {r_3};"));
+            Assert.That(lines[15], Is.EqualTo("\tc_4 -- {r_1};"));
+        }
+
+
+
+        [Test]
+        public void writerTestAdjacency()
+        {
+            DotWriter writer = new DotWriter();
+
+            AdjacencyGraph graph = new AdjacencyGraph();
+            graph.AddEdge(1, 2);
+            graph.AddEdge(1, 5);
+            graph.AddEdge(3, 2);
+            graph.AddEdge(3, 4);
+            graph.AddEdge(4, 1);
+            graph.AddEdge(5, 4);
+
+            string[] lines = writer.Write(graph).Split(
+            new string[] { "\r\n", "\r", "\n" },
+            StringSplitOptions.None
+            );
+
+            Assert.That(lines[2], Is.EqualTo("\tc_2  [shape=circle, style=filled]"));
+            Assert.That(lines[4], Is.EqualTo("\tc_4  [shape=circle, style=filled]"));
+            Assert.That(lines[5], Is.EqualTo("\tc_5  [shape=circle, style=filled]"));
+            Assert.That(lines[7], Is.EqualTo("\tc_3 -- {c_2};"));
+            Assert.That(lines[9], Is.EqualTo("\tc_5 -- {c_1 c_4};"));
+        }
+        
+        
+    }
+}