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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def quote(src_string, return_expr=False):
 """Go from source code to AST nodes. This function returns a tree without enclosing `Module` or `Expr` nodes. Args: src_string: The source code to parse. return_expr: Whether or not to return a containing expression. This can be set to `True` if the result is to be part of a series of statements. Returns: An AST of the given source code. """

  node = parse_string(src_string)
  body = node.body
  if len(body) == 1:
    if isinstance(body[0], gast.Expr) and not return_expr:
      out = body[0].value
    else:
      out = body[0]
  else:
    out = node
  return out