code: def createContactItem(self, person, email):
          
          if email:
              address = self._existing(email)
              if address is not None:
                  raise ValueError('There is already a person with that email '
                                   'address (%s): ' % (address.person.name,))
              return EmailAddress(store=self.store,
                                  address=email,
                                  person=person)
docs: Create a new L{EmailAddress} associated with the given person based on
          the given email address.
  
          @type person: L{Person}
          @param person: The person with whom to associate the new
              L{EmailAddress}.
  
          @type email: C{unicode}
          @param email: The value to use for the I{address} attribute of the
              newly created L{EmailAddress}.  If C{''}, no L{EmailAddress} will
              be created.
  
          @return: C{None}