function _computeRightDomainAdjustment(values) {
  if (values.length > 1) {
    return (values[values.length - 1] - values[values.length - 2]) / 2;
  }
  if (values.length === 1) {
    return values[0] - 0.5;
  }
  return 0;
}
Compute right domain adjustment for the given values.
@param {Array} values Array of values.
@returns {number} Domain adjustment.
@private