isAbsolute property
Whether this object's path is absolute.
An absolute path is independent of the current working directory (Directory.current). A non-absolute path must be interpreted relative to the current working directory.
On Windows, a path is absolute if it starts with \\
(two backslashes or representing a UNC path) or with a drive letter
between a and z (upper or lower case) followed by :\ or :/.
This makes, for example, \file.ext a non-absolute path
because it depends on the current drive letter.
On non-Windows, a path is absolute if it starts with /.
If the path is not absolute, use absolute to get an entity with an absolute path referencing the same object in the file system, if possible.
Implementation
bool get isAbsolute => _isAbsolute(path);