copy method - File class - dart:io library - Dart API

// Copies this file.

// If newPath is a relative path, it is resolved against the current working directory (Directory.current).

// Returns a Future<File> that completes with a File for the copied file.

// If newPath identifies an existing file, that file is removed first. If newPath identifies an existing directory, the operation fails and the future completes with an exception.

// Implementation
Future<File> copy(String newPath);