class_docstr: A ChainMap groups multiple dicts (or other mappings) together
  to create a single, updatable view.
  
  The underlying mappings are stored in a list.  That list is public and can
  be accessed / updated using the *maps* attribute.  There is no other state.
  
  Lookups search the underlying mappings successively until a key is found.
  In contrast, writes, updates, and deletions only operate on the first
  mapping.
docstr: Create a ChainMap with a single dict created from the iterable.
docstr_tok: ["Create","a","ChainMap","with","a","single","dict","created","from","the","iterable","."]
code: def fromkeys(cls, iterable, *args):
      "Create a ChainMap with a single dict created from the iterable."
      return cls(dict.fromkeys(iterable, *args))
  
imports: import sys
label_desc: Use image node_id 10 for calling the ChainMap obj's underlying member method code with example usage: obj.fromkeys(cls, iterable) and returns: cls