code: def _get_schema(name):
    
    item = datalab.utils.commands.get_notebook_item(name)
    if not item:
      item = _get_table(name)
  
    if isinstance(item, datalab.bigquery.Schema):
      return item
    if hasattr(item, 'schema') and isinstance(item.schema, datalab.bigquery._schema.Schema):
      return item.schema
    return None
docs: Given a variable or table name, get the Schema if it exists.