Removes newlines, tabs and whitespaces at the beginning, the end and if there is more than one.

        :param arg: A string, the string which shell be cleaned
        :return: A string, the cleaned string

def delete_whitespaces(self, arg):
        """Removes newlines, tabs and whitespaces at the beginning, the end and if there is more than one.

        :param arg: A string, the string which shell be cleaned
        :return: A string, the cleaned string
        """
        # Deletes whitespaces after a newline
        arg = re.sub(re_newline_spc, '', arg)
        # Deletes every whitespace, tabulator, newline at the beginning of the string
        arg = re.sub(re_starting_whitespc, '', arg)
        # Deletes whitespace or tabulator if followed by whitespace or tabulator
        arg = re.sub(re_multi_spc_tab, '', arg)
        #  Deletes newline if it is followed by an other one
        arg = re.sub(re_double_newline, '', arg)
        # Deletes newlines and whitespaces at the end of the string
        arg = re.sub(re_ending_spc_newline, '', arg)
        return arg