code: def validate_instance_username(self, username):
          ''' Validate instance username '''
          # 1-16 alphanumeric characters - first character must be a letter -
          # cannot be a reserved MySQL word
          if re.match('[\w-]+$', username) is not None:
              if len(username) <= 16 and len(username) >= 1:
                  if username[0].isalpha():
                      if username not in MYSQL_RESERVED_WORDS:
                          return True
          return '*** Error: Usernames must be 1-16 alphanumeric chracters, \
              first a letter, cannot be reserved MySQL word.f validate_instance_username(self, username):
          ''' Validate instance username '''
          # 1-16 alphanumeric characters - first character must be a letter -
          # cannot be a reserved MySQL word
          if re.match('[\w-]+$', username) is not None:
              if len(username) <= 16 and len(username) >= 1:
                  if username[0].isalpha():
                      if username not in MYSQL_RESERVED_WORDS:
                          return True
          return '*** Error: Usernames must be 1-16 alphanumeric chracters, \
              first a letter, cannot be reserved MySQL word.'
docs: Validate instance username