code: function ( qu, value ) {
  		var operands = sys.flatten( qu.operands );
  		if ( operands.length !== 2 ) {
  			throw new Error( "$mod requires two operands" );
  		}
  		var mod = operands[0];
  		var rem = operands[1];
  		return value % mod === rem;
  	}
docs: Checks equality to a modulus operation on a field
  `{field: {$mod: [divisor, remainder]}}`
  @name $mod
  @memberOf module:documents/probe.queryOperators
  @example
  var probe = require("documents/probe");
  probe.find( data, {"age" : {$mod : [2, 0]}} );