protected Token eat(TokenKind expectedKind) {
		Token t = next();
		if (t == null) {
			raiseException(expression.length(), JobDSLMessage.OOD);
		}
		if (t.kind != expectedKind) {
			raiseException(t.startpos, JobDSLMessage.NOT_EXPECTED_TOKEN,
					expectedKind.toString().toLowerCase(),
					t.getKind().toString().toLowerCase() + (t.data == null ? "" : "(" + t.data + ")"));
		}
		return t;
	}
Consume the next token if it matches the indicated token kind;
otherwise throw {@link CheckpointedJobDefinitionException}.

@param expectedKind the expected token kind
@return the next token
@throws CheckpointedJobDefinitionException if the next token does not match
the expected token kind
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/job/dsl/Tokens.java