Object validator interface. Implementors of this class can be added to
any
com.itmill.toolkit.data.Validatable
object to verify
its value. The
Validatable#isValid(Object)
iterates all
registered
Validator
s, calling their
validate(java.lang.Object)
methods.
validate(Object)
should throw the
com.itmill.toolkit.data.Validator.InvalidValueException
if the given value is not valid
by its standards.