Compares this instance to a specified object and returns an indication of their relative values.
A 32-bit signed integer that indicates the relative order of the values compared. The return value has these meanings:
|Less than zero||This instance is less than r.|
|Zero||This instance is equal to r.|
|Greater than zero||
This instance is greater than r.
r is a null reference (Nothing in Visual Basic).
r must be an instance of Level or a null reference (Nothing in Visual Basic); otherwise, an exception is thrown.