@Override
		public String getText(Interval interval) {
			int startIdx = Math.min(interval.a, size);
			int len = Math.min(interval.b - interval.a + 1, size - startIdx);

			// Note that we pass the int[] code points to the String constructor --
			// this is supported, and the constructor will convert to UTF-16 internally.
			return new String(intArray, startIdx, len);
		}
Return the UTF-16 encoded string for the given interval
runtime/Java/src/org/antlr/v4/runtime/CodePointCharStream.java