Base class for keys events with modifiers.
Contains keys events information with modifiers support like [kbd]Shift[/kbd] or [kbd]Alt[/kbd]. See [method Node._input].
$DOCS_URL/tutorials/inputs/inputevent.html
- State of the [kbd]Alt[/kbd] modifier.
- State of the [kbd]Command[/kbd] modifier.
- State of the [kbd]Ctrl[/kbd] modifier.
- State of the [kbd]Meta[/kbd] modifier.
- State of the [kbd]Shift[/kbd] modifier.