opendap/src/main/java/opendap/servers/SDUInt32.java
public boolean equal(BaseType bt) throws InvalidOperatorException, RegExpException, SBHException {
        return (Operator.op(EQUAL, this, bt));
    }
public boolean equal(BaseType bt) throws InvalidOperatorException, RegExpException, SBHException {
        return (Operator.op(EQUAL, this, bt));
    }
The RelOps interface defines how each type responds to relational
operators. Most (all?) types will not have sensible responses to all of
the relational operators (e.g. DInt won't know how to match a regular
expression but DString will). For those operators that are nonsensical a
class should throw InvalidOperatorException.