ReflectionUtils.rethrowRuntimeException(var2.getTargetException());

This line of code is part of the Spring Framework's ReflectionUtils class. It is used to rethrow an exception that was caught during a method invocation using reflection.

The method takes in an exception object (var2), which is expected to be an instance of InvocationTargetException. This exception is thrown when a reflective method invocation fails because the invoked method itself threw an exception.

The rethrowRuntimeException() method extracts the original exception that was thrown by the invoked method (i.e., the target exception) and rethrows it as a RuntimeException. This is useful when the original exception is checked and the caller does not want to declare it in a throws clause or handle it explicitly.

In summary, this code is used to propagate an exception that was thrown by a method invoked via reflection as a runtime exception, without requiring the caller to catch or declare the checked exception.