Returns a composed function that first applies the before function to its input, and then applies this function to the result. If evaluation of either function throws an exception, it is relayed to the caller of the composed function.

Parameters:

<V>		the type of input to the before function, and to the composed function
before		the function to apply before this function is applied

Returns:  a composed function that first applies the before function and then applies this function

Exceptions:

NullPointerException

if before is null

See also:
andThen(Function)