code: def __init__(self, start, end, source=None):
      self.start = start
      self.end = end
      self.source = source
  
imports: from .None import ast
  from ..error import GraphQLSyntaxError
  from .lexer import Lexer, TokenKind, get_token_desc, get_token_kind_desc
  from .source import Source
label_desc: Use image node_id 1 to create a new Loc object from inherited base classes: object with example: obj = Loc(start, end, source)