@Override
	public String getMessage() {
		StringBuilder s = new StringBuilder();
		if (message != null) {
			s.append(message.formatMessage(position, inserts));
		}
		else {
			s.append(super.getMessage());
		}
		if (expressionString != null && expressionString.length() > 0) {
			s.append("\n").append(expressionString).append("\n");
		}
		if (position >= 0) {
			for (int i = 0; i < position; i++) {
				s.append(' ');
			}
			s.append("^\n");
		}
		return s.toString();
	}
@return a formatted message with inserts applied
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/stream/dsl/StreamDefinitionException.java