I use the command create a custom app

"c:\Program Files (x86)\Odoo 11.0\python\python.exe" "c:\Program Files (x86)\Odoo 11.0\server\odoo-bin" scaffold custom4 "C:\Users\user1\Downloads\1"

and run succeffaully. But I see the custom4/models.py as below:

class 'custom4(models.Model):
    _name = 'custom4.'custom4

I want to modify the class name as mymodel

class mymodel(models.Model):
    _name = 'custom4.mymodel'

and include the custom4/views/views.xml

I replace the custom4.custom4 with custom4.mymodel.

After modify the model class name, I upgrade the custom app. It cause the Odd Server Error.

Model not found: custom4.mymodel
Error context:
View `custom4 list`
[view_id: 1479, xml_id: custom4.list, model: custom4.mymodel, parent_id: n/a]
None" while parsing file:/c:/users/user1/downloads/1/custom4/views/views.xml:5, near
<record model="ir.ui.view" id="custom4.list">
      <field name="name">custom4 list</field>
      <field name="model">custom4.mymodel</field>
      <field name="arch" type="xml">
        <tree>
          <field name="name"/>
          <field name="value"/>
          <field name="value2"/>
        </tree>
      </field>
    </record>

Does somebody know how to achieve this goal？