parameters: (self, stmt)
docstring: Marks the beginning of a statement.
  
      Args:
        stmt: Hashable, a key by which the statement can be identified in the
          CFG's stmt_prev and stmt_next attributes
docstring_summary: Marks the beginning of a statement.
docstring_tokens: Marks the beginning of a statement .
function: def begin_statement(self, stmt):
      """Marks the beginning of a statement.
  
      Args:
        stmt: Hashable, a key by which the statement can be identified in the
          CFG's stmt_prev and stmt_next attributes
      """
      self.active_stmts.add(stmt)
function_tokens: def begin_statement ( self , stmt ) : self . active_stmts . add ( stmt )