code: def parse(code, filename='<unknown>', mode='exec', tree=None):
      
      visitor = Visitor(code, filename, mode, tree=tree)
      return visitor.tree
docs: Parse the source into an AST node with PyPosAST.
      Enhance nodes with positions
  
  
      Arguments:
      code -- code text
  
  
      Keyword Arguments:
      filename -- code path
      mode -- execution mode (exec, eval, single)
      tree -- current tree, if it was optimized