'Add an email field to a form description.
Arguments:
form_desc: A form description
Keyword Arguments:
required (bool): Whether this field is required; defaults to True'

def _add_email_field(self, form_desc, required=True):

    email_label = _(u'Email')
    email_placeholder = _(u'username@domain.com')
    email_instructions = _(u'This    is    what    you    will    use    to    login.')
    form_desc.add_field('email', field_type='email', label=email_label, placeholder=email_placeholder, instructions=email_instructions, restrictions={'min_length': accounts.EMAIL_MIN_LENGTH, 'max_length': accounts.EMAIL_MAX_LENGTH}, required=required)
