function between(propertyName, lowerBoundary, upperBoundary) {
  return new IsBetween(propertyName, lowerBoundary, upperBoundary);
}
Creates a `<PropertyIsBetween>` comparison operator to test whether an expression
value lies within a range given by a lower and upper bound (inclusive).

@param {!string} propertyName Name of the context property to compare.
@param {!number} lowerBoundary The lower bound of the range.
@param {!number} upperBoundary The upper bound of the range.
@return {!IsBetween} `<PropertyIsBetween>` operator.
@api