I create a custom module which create a function in product module 

to import products from cvs file and it work fine in community version 

import csv
from odoo import api, models

class ProductProduct(models.Model):
    _inherit = 'product.template'

    def process_csv_file(self, file_path):
# and rest of code

but when I convert it to zip and import it in enterprise version
I get this Error

AttributeError: 'product.template' object has no attribute 'process_csv_file'

so why this error