class_docstr: An object to assist in building Vega-Lite Expressions
class_docstr_tok: ["An","object","to","assist","in","building","Vega-Lite","Expressions"]
docstr: Specify a datum for use in an encoding
docstr_tok: ["Specify","a","datum","for","use","in","an","encoding"]
code: def __call__(self, datum, **kwargs):
      """Specify a datum for use in an encoding"""
      return dict(datum=datum, **kwargs)
  
imports: from ..utils import SchemaBase
label_desc: Use image node_id 4 for calling the DatumType obj's underlying member method code with example usage: obj.__call__(datum) and returns: dict