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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def customize_form_field(self, name, field):
 """ Allows views to customize their form fields. By default, Smartmin replaces the plain textbox date input with it's own DatePicker implementation. """

        if isinstance(field, forms.fields.DateField) and isinstance(field.widget, forms.widgets.DateInput):
            field.widget = widgets.DatePickerWidget()
            field.input_formats = [field.widget.input_format[1]] + list(field.input_formats)

        if isinstance(field, forms.fields.ImageField) and isinstance(field.widget, forms.widgets.ClearableFileInput):
            field.widget = widgets.ImageThumbnailWidget()

        return field