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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 html_email(email, title=None):
 """ '<a href="mailto:username@example.com">username@example.com</a>' """


    if not title:
        title = email

    return '<a href="mailto:{email}">{title}</a>'.format(email=email, title=title)