nl_tokens: Recursively copies given object into a new object . Helper method for merge
pl_tokens: function clone ( v ) { if ( v === null || typeof v !== "object" ) { return v ; } if ( isArray ( v ) ) { var arr = v . <mask> ( ) ; for ( var i = 0 ; i < v . length ; i ++ ) { arr [ i ] = clone ( arr [ i ] ) ; } return arr ; } else { var obj = { } ; for ( var k in v ) { obj [ k ] = clone ( v [ k ] ) ; } return obj ; } }