reactor-core/src/main/java/reactor/util/function/Tuple6.java
public <R> Tuple6<R, T2, T3, T4, T5, T6> mapT1(Function<T1, R> mapper) {
		return new Tuple6<>(mapper.apply(t1), t2, t3, t4, t5, t6);
	}
public <R> Tuple6<R, T2, T3, T4, T5, T6> mapT1(Function<T1, R> mapper) {
		return new Tuple6<>(mapper.apply(t1), t2, t3, t4, t5, t6);
	}
public < R > Tuple6 < R , T2 , T3 , T4 , T5 , T6 > mapT1 ( Function < T1 , R > mapper ) { return new Tuple6 <> ( mapper . apply ( t1 ) , t2 , t3 , t4 , t5 , t6 ) ; }
Map the 1st part (T1) of this {@link Tuple6} into a different value and type,
keeping the other parts.

@param mapper the mapping {@link Function} for the T1 part
@param <R> the new type for the T1 part
@return a new {@link Tuple6} with a different T1 value
Map the 1st part ( T1 ) of this { @link Tuple6 } into a different value and type keeping the other parts .