human
I wrote the below code

    T = current.T
    db = current.db
    s3db = current.s3db
    s3 = current.response.s3
    settings = current.deployment_settings
    tablename = 'supply_item_entity'
    table = s3db[tablename]
    s3.crud_strings[tablename] = Storage(label_create=T('Add    Item'), title_display=T('Item    Details'), title_list=T('Items'), title_update=T('Edit    Item'), label_list_button=T('List    Items'), label_delete_button=T('Delete    Item'), msg_record_created=T('Item    added'), msg_record_modified=T('Item    updated'), msg_record_deleted=T('Item    deleted'), msg_list_empty=T('No    Items    currently    registered'))
    table.category = Field.Method('category', supply_item_entity_category)
    table.country = Field.Method('country', supply_item_entity_country)
    table.organisation = Field.Method('organisation', supply_item_entity_organisation)
    table.contacts = Field.Method('contacts', supply_item_entity_contacts)
    table.status = Field.Method('status', supply_item_entity_status)
    s3.no_sspag = True
    s3db.configure(tablename, deletable=False, insertable=False, list_fields=[(T('Category'), 'category'), 'item_id', 'quantity', (T('Unit    of    Measure'), 'item_pack_id'), (T('Status'), 'status'), (current.messages.COUNTRY, 'country'), (T('Organization'), 'organisation'), (T('Contacts'), 'contacts')], extra_fields=['instance_type'])
    def postp(r, output):
        if (r.interactive and (not r.record)):
            rheader = DIV()
            table = s3db.supply_item_category
            etable = s3db.supply_item_entity
            itable = s3db.supply_item
            query = (((etable.deleted == False) & (etable.item_id == itable.id)) & (itable.item_category_id == table.id))
            categories = db(query).select(table.id, table.name, distinct=True)
            select = SELECT(_multiple='multiple', _id='category_dropdown')
            for category in categories:
                select.append(OPTION(category.name, _name=category.id))
            rheader.append(DIV(B(('%s:' % T('Filter    by   ...

What's a good function header?
 ... Here's a good function header?
assistant
#Here's a good function header.

def supply_item_entity_controller():