operator == method
Compares two length for equality.
Implementation
@override
bool operator ==(Object? other) {
  return (other == null && (type == CSSLengthType.UNKNOWN || type == CSSLengthType.INITIAL)) ||
      (other is CSSLengthValue &&
          other.value == value &&
          other.calcValue == calcValue &&
          (isZero || other.type == type));
}