by<A, B> static method
Convert an implicit PartialOrder[B]
to an PartialOrder[A]
using the given
function f
.
Implementation
static PartialOrder<A> by<A, B>(B Function(A a) f, PartialOrder<B> po) =>
_PartialOrder<A>((x, y) => po.partialCompare(f(x), f(y)));