Add example

docs/API.md

@@ -122,6 +122,23 @@ With [`stream()`](#streamfunction-options), whether the command result should:
 - `save`: [be pushed](https://github.com/sindresorhus/execa#childprocessresult)
   to the `file.execa` array property
 
+```js
+const { src } = require('gulp')
+const { stream } = require('gulp-execa')
+const through = require('through2')
+
+module.exports.default = () =>
+  src('**/*')
+    // Prints the number of lines of each file
+    .pipe(stream(({ path }) => `wc -l ${path}`, { result: 'save' }))
+    .pipe(
+      through.obj((file, encoding, func) => {
+        console.log(file.execa[0].stdout)
+        func(null, file)
+      }),
+    )
+```
+
 #### from
 
 _Type_: `string`<br> _Value_: `'stdout'`, `'stderr'` or `'all'`<br> _Default_: