clean method for bulk edit method is not getting called

[vmathurpaytm]

Model
file_item = models.FileField(blank=False, verbose_name=_('ABC'),)

Admin

def ModelAdmin():
     action = ['bulk_edit_action']
     bulk_list_display = ['file_item']
     form = FileFieldForm 

def FileFieldForm(RalphAdminForm):
    file_item = forms.FileField()
    def clean_file_item():
         # do some stuff

Expected behaviour
Want this file field clean method to be called