old_contents: 
  class ClusterAbstraction(object):
      """Get cluster abstraction based on longest common substring.
  
      References
      ----------
      .. [1] jtjacques, Longest common substring from more than two strings - Python.
             http://stackoverflow.com/questions/2892931/longest-common-substring-from-more-than-two-strings-python.
      """
      @staticmethod
      def dp_lcs(graph, clusters):
          """The processed string are preprocessed message from raw event log messages.
  
          Parameters
          ----------
          graph       : graph
              A graph to be processed.
          clusters    : dict[list]
              Dictionary containing a list of node identifier per cluster.
          Returns
          -------
          abstraction : dict[str]
              Dictionary of abstraction string per cluster.
          """
          abstraction = {}
          for cluster_id, nodes in clusters.iteritems():
              data = []
              for node_id in nodes:
                  data.append(graph.node[node_id]['preprocessed_event'])
              abstraction[cluster_id] = ClusterAbstraction.lcs(data)
  
          return abstraction
  
      @staticmethod
      def lcs(data):
          """Get longest common substring from multiple string.
  
          Parameters
          ----------
          data    : list[str]
              List of string to be processed.
          Returns
          -------
          substr  : str
              A single string as longest common substring.
          """
          substr = ''
          if len(data) > 1 and len(data[0]) > 0:
              for i in range(len(data[0])):
                  for j in range(len(data[0]) - i + 1):
                      if j > len(substr) and all(data[0][i:i + j] in x for x in data):
                          substr = data[0][i:i + j]
  
          return substr
  
new_contents: 
  class ClusterAbstraction(object):
      """Get cluster abstraction based on longest common substring [jtjacques2010]_.
  
      References
      ----------
      .. [jtjacques2010] jtjacques, Longest common substring from more than two strings - Python.
             http://stackoverflow.com/questions/2892931/longest-common-substring-from-more-than-two-strings-python.
      """
      @staticmethod
      def dp_lcs(graph, clusters):
          """The processed string are preprocessed message from raw event log messages.
  
          Parameters
          ----------
          graph       : graph
              A graph to be processed.
          clusters    : dict[list]
              Dictionary containing a list of node identifier per cluster.
          Returns
          -------
          abstraction : dict[str]
              Dictionary of abstraction string per cluster.
          """
          abstraction = {}
          for cluster_id, nodes in clusters.iteritems():
              data = []
              for node_id in nodes:
                  data.append(graph.node[node_id]['preprocessed_event'])
              abstraction[cluster_id] = ClusterAbstraction.lcs(data)
  
          return abstraction
  
      @staticmethod
      def lcs(data):
          """Get longest common substring from multiple string.
  
          Parameters
          ----------
          data    : list[str]
              List of string to be processed.
          Returns
          -------
          substr  : str
              A single string as longest common substring.
          """
          substr = ''
          if len(data) > 1 and len(data[0]) > 0:
              for i in range(len(data[0])):
                  for j in range(len(data[0]) - i + 1):
                      if j > len(substr) and all(data[0][i:i + j] in x for x in data):
                          substr = data[0][i:i + j]
  
          return substr
  
subject: Fix bug in docstring references