parameters: (self, node_type)
docstring: Find the first node of a given type.  If no such node exists the
          return value is `None`.
docstring_summary: Find the first node of a given type.  If no such node exists the
          return value is `None`.
docstring_tokens: Find the first node of a given type . If no such node exists the return value is None .
function: def find(self, node_type):
          """Find the first node of a given type.  If no such node exists the
          return value is `None`.
          """
          for result in self.find_all(node_type):
              return result
function_tokens: def find ( self , node_type ) : for result in self . find_all ( node_type ) : return result