code: def get_function(self):
      def cum_sum(values):
          return values.cumsum()
  
      return cum_sum
  
imports: from woodwork.column_schema import ColumnSchema
  from featuretools.primitives.base import TransformPrimitive
label_desc: Use image node_id 1 for calling the CumSum obj's underlying member method code with example usage: obj.get_function() and returns: cum_sum, values