text: """
      Tests for Group Centrality Measures
  """
  
  
  import pytest
  import networkx as nx
  
  
  class TestGroupBetweennessCentrality:
      def test_group_betweenness_single_node(self):
          """
              Group betweenness centrality for single node group
          """
          G = nx.path_graph(5)
          C = [1]
          b = nx.group_betweenness_centrality(G, C, weight=None, normalized=False)
          b_answer = 3.0
          assert b == b_answer
  
      def test_group_betweenness_normalized(self):
          """
              Group betweenness centrality for group with more than
              1 node and normalized
          """
          G = nx.path_graph(5)
          C = [1, 3]
          b = nx.group_betweenness_centrality(G, C, weight=None, normalized=True)
          b_answer = 1.0
          assert b == b_answer
  
      def test_group_betweenness_value_zero(self):
          """
              Group betweenness centrality value of 0
          """
          G = nx.cycle_graph(6)
          C = [0, 1, 5]
          b = nx.group_betweenness_centrality(G, C, weight=None)
          b_answer = 0.0
          assert b == b_answer
  
      def test_group_betweenness_disconnected_graph(self):
          """
              Group betweenness centrality in a disconnected graph
          """
          G = nx.path_graph(5)
          G.remove_edge(0, 1)
          C = [1]
          b = nx.group_betweenness_centrality(G, C, weight=None)
          b_answer = 0.0
          assert b == b_answer
  
      def test_group_betweenness_node_not_in_graph(self):
          """
              Node(s) in C not in graph, raises NodeNotFound exception
          """
          with pytest.raises(nx.NodeNotFound):
              b = nx.group_betweenness_centrality(nx.path_graph(5), [6, 7, 8])
  
  
  class TestGroupClosenessCentrality:
      def test_group_closeness_single_node(self):
          """
              Group closeness centrality for a single node group
          """
          G = nx.path_graph(5)
          c = nx.group_closeness_centrality(G, [1])
          c_answer = nx.closeness_centrality(G, 1)
          assert c == c_answer
  
      def test_group_closeness_disconnected(self):
          """
              Group closeness centrality for a disconnected graph
          """
          G = nx.Graph()
          G.add_nodes_from([1, 2, 3, 4])
          c = nx.group_closeness_centrality(G, [1, 2])
          c_answer = 0
          assert c == c_answer
  
      def test_group_closeness_multiple_node(self):
          """
              Group closeness centrality for a group with more than
              1 node
          """
          G = nx.path_graph(4)
          c = nx.group_closeness_centrality(G, [1, 2])
          c_answer = 1
          assert c == c_answer
  
      def test_group_closeness_node_not_in_graph(self):
          """
              Node(s) in S not in graph, raises NodeNotFound exception
          """
          with pytest.raises(nx.NodeNotFound):
              c = nx.group_closeness_centrality(nx.path_graph(5), [6, 7, 8])
  
  
  class TestGroupDegreeCentrality:
      def test_group_degree_centrality_single_node(self):
          """
              Group degree centrality for a single node group
          """
          G = nx.path_graph(4)
          d = nx.group_degree_centrality(G, [1])
          d_answer = nx.degree_centrality(G)[1]
          assert d == d_answer
  
      def test_group_degree_centrality_multiple_node(self):
          """
              Group degree centrality for group with more than
              1 node
          """
          G = nx.Graph()
          G.add_nodes_from([1, 2, 3, 4, 5, 6, 7, 8])
          G.add_edges_from(
              [(1, 2), (1, 3), (1, 6), (1, 7), (1, 8), (2, 3), (2, 4), (2, 5)]
          )
          d = nx.group_degree_centrality(G, [1, 2])
          d_answer = 1
          assert d == d_answer
  
      def test_group_in_degree_centrality(self):
          """
              Group in-degree centrality in a DiGraph
          """
          G = nx.DiGraph()
          G.add_nodes_from([1, 2, 3, 4, 5, 6, 7, 8])
          G.add_edges_from(
              [(1, 2), (1, 3), (1, 6), (1, 7), (1, 8), (2, 3), (2, 4), (2, 5)]
          )
          d = nx.group_in_degree_centrality(G, [1, 2])
          d_answer = 0
          assert d == d_answer
  
      def test_group_out_degree_centrality(self):
          """
              Group out-degree centrality in a DiGraph
          """
          G = nx.DiGraph()
          G.add_nodes_from([1, 2, 3, 4, 5, 6, 7, 8])
          G.add_edges_from(
              [(1, 2), (1, 3), (1, 6), (1, 7), (1, 8), (2, 3), (2, 4), (2, 5)]
          )
          d = nx.group_out_degree_centrality(G, [1, 2])
          d_answer = 1
          assert d == d_answer
  
      def test_group_degree_centrality_node_not_in_graph(self):
          """
              Node(s) in S not in graph, raises NetworkXError
          """
          with pytest.raises(nx.NetworkXError):
              b = nx.group_degree_centrality(nx.path_graph(5), [6, 7, 8])
  