question: public static void upto ( Number self , Number to , @ ClosureParams ( FirstParam . class ) Closure closure ) { int self1 = self . intValue ( ) ; int to1 = to . intValue ( ) ; if ( self1 <= to1 ) { for ( int i = self1 ; i <= to1 ; i ++ ) { closure . call ( i ) ; } } else throw new GroovyRuntimeException ( "The argument (" + to + ") to upto() cannot be less than the value (" + self + ") it's called on." ) ; }
target:  Iterates from this number up to the given number, inclusive, incrementing by one each time.