@Override
	public boolean isPositionDependent() {
		return true;
	}
Gets whether the lexer action is position-dependent. Position-dependent
actions may have different semantics depending on the {@link CharStream}
index at the time the action is executed.

<p>Custom actions are position-dependent since they may represent a
user-defined embedded action which makes calls to methods like
{@link Lexer#getText}.</p>

@return This method returns {@code true}.
runtime/Java/src/org/antlr/v4/runtime/atn/LexerCustomAction.java