@Override
	public boolean equivalent( X x, Y y ) {
		if ( x == null && y == null )
			return true;
		if ( x == null || y == null )
			return false;
		return x.equals( y );
	}
@ Override public boolean equivalent ( X x , Y y ) { if ( x == null && y == null ) return true ; if ( x == null || y == null ) return false ; return x . equals ( y ) ; }
<p>
{@code equivalent} relies on {@link java.lang.Object#equals(Object) equals}
to tell whether two objects are equivalent or not. When both arguments are
{@code null}, it returns {@code true}. When one is {@code null} and the
other is not {@code null}, it returns {@code false}. Otherwise, it invokes
{@link java.lang.Object#equals(Object) equals} on the
<strong>first</strong> object, passing the second object as argument.
</p>

@param x
The first object of the comparison.
@param y
The second object of the comparison.
@return {@code true} when the arguments are equivalent. {@code false}
otherwise.
@since 1.0