@SuppressWarnings("unchecked")
	private void initFingerprints() {
		if (fingerprints.isEmpty()) {
			for (String sample : this.samples) {
				try {
					// we're only interested in the exception, which is currently
					// not influenced by the kind of parse. Use stream for now
					this.parser.parse("__dummy", sample, ParsingContext.partial_stream);
				}
				catch (RuntimeException exception) {
					if (this.exceptionClass.isAssignableFrom(exception.getClass())) {
						computeFingerprint((E) exception);
					}
					else {
						throw exception;
					}
				}
			}
		}
	}
Construct a new StacktraceFingerprintingCompletionRecoveryStrategy given the parser, and the expected exception
class to be thrown for sample fragments of a stream definition that is to be parsed.

@param parser the parser used to parse the sample fragment stream definitions.
@param exceptionClass the expected exception that results from parsing the sample fragment stream definitions.
       Stack frames from the thrown exception are used to store the fingerprint of this exception thrown by the
       parser.
@param samples the sample fragments of stream definitions.
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/stream/completion/StacktraceFingerprintingCompletionRecoveryStrategy.java