docs: def insert_statement(table, columns, values):
      """Generate an insert statement string for dumping to text file or MySQL execution."""
      if not all(isinstance(r, (list, set, tuple)) for r in values):
          values = [[r] for r in values]
      rows = []
      for row in values:
          new_row = []
          for col in row:
              if col is None:
                  new_col = 'NULL'
              elif isinstance(col, (int, float, Decimal)):
                  new_col = str(MySQLConverterBase().to_mysql(col))
              else:
                  string = str(MySQLConverterBase().to_mysql(col))
                  if "'" in string:
                      new_col = '"' + string + '"'
                  else:
                      new_col = "'" + string + "'"
              new_row.append(new_col)
          rows.append(', '.join(new_row))
      vals = '(' + '),\n\t('.join(rows) + ')'
      statement = "INSERT INTO\n\t{0} ({1}) \nVALUES\n\t{2}".format(wrap(table), cols_str(columns), vals)
      return statement