function resolve( operation ) {
	var t = ( typeof operation );
	if ( t === 'number' ) {
		return ( enum2str( operation ) ) ? operation : null;
	}
	if ( t === 'string' ) {
		return str2enum( operation );
	}
	return null;
}
Returns the enumeration constant associated with a supported BLAS operation side value.

## Notes

-   Downstream consumers of this function should **not** rely on specific integer values (e.g., `LEFT == 0`). Instead, the function should be used in an opaque manner.

@param {*} operation - operation value
@returns {(integer|null)} enumeration constant or null

@example
var v = resolve( 'right' );
// returns <number>