creates a text report for the human user
        :return: str

def create_report(self):
        """
        creates a text report for the human user
        :return: str
        """

        if self.report:
            self.report += "\n Operation took %s secs" % round(
                time.time() - self.t1)
        else:
            self.report = "Operation failed: %s \n" % self.report
        return self.report