class_docstr: Simple, type-checked, dict-like container for with submessage values.
class_docstr_tok: ["Simple",",","type-checked",",","dict-like","container","for","with","submessage","values","."]
code: def __contains__(self, item):
      return item in self._values
  
imports: import collections
  import sys
label_desc: Use image node_id 5 for calling the MessageMap obj's underlying member method code with example usage: obj.__contains__(item) and returns: unknown