'Returns a value form a document
:param doctype: DocType to be queried
:param fieldname: Field to be returned (default `name`)
:param filters: dict or string for identifying the record'

def get_value(self, doctype, fieldname=None, filters=None):

    return self.get_request({'cmd': 'frappe.client.get_value', 'doctype': doctype, 'fieldname': (fieldname or 'name'), 'filters': frappe.as_json(filters)})
