function assertNoExtraCurrentStyling(blocks, expectedCurrent = undefined) {
    for (let block, i = 0; (block = blocks[i]); i++) {
      const isCurrentStyled = isBlockCurrentStyled(block);
      if (isCurrentStyled) {
        assert.equal(
          expectedCurrent,
          block,
          'Unexpected block [' + block.type + '] found styled as current.',
        );
      } else {
        assert.notEqual(
          block,
          expectedCurrent,
          'Expected block [' + block.type + '] to be styled as current.',
        );
      }
    }
  }
Assert that no extra styling is currently added to these blocks.
@param {Array.<Blockly.BlockSvg>} blocks The blocks to test.
@param {Blockly.BlockSvg=} expectedCurrent Optional, block that is
    expected.