图片下载工具案例，用于 Node.js 教学参考。
Resolve a URI relative to an optional base URI
An HTTP(s) proxy `http.Agent` implementation for HTTPS
A simple common HTTP client specifically for Google APIs and services.
parse argument options
Native Abstractions for Node.js: C++ header for Node 0.8 -> 26 compatibility
Toggle current selected content in browser
Offers getProxyForUrl to get the proxy URL for a URL, respecting the *_PROXY (e.g. HTTP_PROXY) and NO_PROXY environment variables.
The core `url` packaged standalone for use with Browserify.
Require global variables
A Node.js module for sending notifications on native Mac, Windows (post and pre 8) and Linux (or Growl as fallback)
JSON.parse with context information on error
for adding, subtracting, and indexing discontinuous ranges of numbers
Standard Subresource Integrity library -- parses, serializes, generates, and verifies integrity metadata according to the SRI spec.
Get and robustly cache all JS language-level intrinsics at first require time
resolve like require.resolve() on behalf of files asynchronously and synchronously
Implementation of Function.prototype.bind
Extendable client for GitHub's REST & GraphQL APIs
Determines if an object can be used as an array
Microsoft Azure SDK for JavaScript - Aborter
hast utility to transform to preact, react, solid, svelte, vue, etc
Determine if the JS environment has Symbol support. Supports spec, or shams.
remark plugin that turns markdown into HTML to support rehype
Does the environment have full property descriptor support? Handles IE 8's broken defineProperty/gOPD.