question: private static String extractErrorSummary ( Throwable e ) { StringBuilder errorMessageBuilder = new StringBuilder ( ) ; Throwable cause = e ; errorMessageBuilder . append ( cause . getLocalizedMessage ( ) ) ; while ( cause != null ) { StackTraceElement [ ] stackTraceElements = cause . getStackTrace ( ) ; errorMessageBuilder . append ( stackTraceElements . length > 0 ? "\n caused by: " + stackTraceElements [ 0 ] : "" ) ; cause = cause . getCause ( ) ; } return errorMessageBuilder . toString ( ) ; }
target:  Extract the meaningful part of a stack trace: a. the causes in the stack trace hierarchy b. the top exception for each cause