class_docstr: A proxy to access variables defined in a layer. 
docstr: Returns:
      list of all variables
docstr_tok: ["Returns",":","list","of","all","variables"]
code: def all(self):
      """
      Returns:
          list of all variables
      """
      return list(six.itervalues(self._vars))
  
imports: import six
label_desc: Use image node_id 5 for calling the VariableHolder obj's underlying member method code with example usage: obj.all() and returns: list