code: def test_linemerge(self):
      lines = MultiLineString(
          [[(0, 0), (1, 1)], [(2, 0), (2, 1), (1, 1)]]
      )
      result = linemerge(lines)
      assert isinstance(result, LineString)
      assert not result.is_ring
      assert len(result.coords) == 4
      assert result.coords[0] == (0.0, 0.0)
      assert result.coords[3] == (2.0, 0.0)
  
      lines2 = MultiLineString(
          [((0, 0), (1, 1)), ((0, 0), (2, 0), (2, 1), (1, 1))]
      )
      result = linemerge(lines2)
      assert result.is_ring
      assert len(result.coords) == 5
  
      lines3 = [
          LineString([(0, 0), (1, 1)]),
          LineString([(0, 0), (0, 1)]),
      ]
      result = linemerge(lines3)
      assert not result.is_ring
      assert len(result.coords) == 3
      assert result.coords[0] == (0.0, 1.0)
      assert result.coords[2] == (1.0, 1.0)
  
      lines4 = [
          [(0, 0), (1, 1)],
          [(0, 0), (0, 1)],
      ]
      assert result.equals(linemerge(lines4))
  
      lines5 = [
          ((0, 0), (1, 1)),
          ((1, 0), (0, 1)),
      ]
      result = linemerge(lines5)
      assert result.geom_type == "MultiLineString"
  
imports: import unittest
  from shapely.geometry import LineString, MultiLineString
  from shapely.ops import linemerge
label_desc: Use image node_id 1 for calling the LineMergeTestCase obj's underlying member method code with example usage: obj.test_linemerge() without return types