== uses compareTo if groovy class is a comparable

class CP implements Comparable
{
int number

int compareTo(obj)

boolean equals(obj)

}

// script
def cp1 = new CP(number:1)
def cp2 = new CP(number:2)
cp1==cp2

// results
if CP implements Comparable, compareTo is called, if not, equals is called

// using grails with above as follows has ominous implications

I have a setup similar to as follows:
TopLevelDomainClass

SubLevelDomainClass implements Comparable
{
int number
int compareTo(obj)

}

sublevel1==sublevel2 calls the compareTo function for evaluation