private char[] subarray(int start, int end) {
		char[] result = new char[end - start];
		System.arraycopy(toProcess, start, result, 0, end - start);
		return result;
	}
To prevent the need to quote all argument values, this identifier lexing function is used just after an '=' when
we are about to digest an arg value. It is much more relaxed about what it will include in the identifier.
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/job/dsl/Tokenizer.java