method O.filterimport { O } from "https://deno.land/x/ahh@v0.10.3/src/option/mod.ts"; filter<T>(opt: Option<T>, f: (_: T) => boolean): Option<T>Calls f with opt, and returns it if the result is true. ExamplesExample 1 import { O, None } from "./mod.ts"; console.log(O.filter(2, (i) => i % 2 === 0)); // 2 console.log(O.filter(1, (i) => i % 2 === 0)); // None console.log(O.filter(None, (i: number) => i % 2 === 0)); // None Type ParametersTParametersopt: Option<T>f: (_: T) => booleanReturnsOption<T>