from itertools import chain
from django.contrib import admin
-from django.contrib.admin.widgets import FilteredSelectMultiple
from django.forms import ModelForm
-from django.forms.fields import Field, CharField
+from django.forms.fields import CharField
from django.forms.widgets import TextInput, Select
from django.utils.encoding import force_text
from django.utils.html import escape, conditional_escape
-from django.utils.translation import ugettext_lazy as _
from .models import (
FlowCell,