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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 get_field_class(qs, field_name):
 """ Given a queryset and a field name, it will return the field's class """

    try:
        return qs.model._meta.get_field(field_name).__class__.__name__
    # while annotating, it's possible that field does not exists.
    except FieldDoesNotExist:
        return None