Unable to redirect all the eclipse console logs to buffer

I need to assert some string present in the console logs. I tried the below code to redirect the console logs to buffer. However, still some part of the code goes to console logs and I am unable to assert it programatically. Could someone help me here ?

System.setOut( new PrintStream(new ByteArrayOutputStream()));

Assertions and exceptions are sent to the Error stream, so if you are looking to assert these you should also set the error stream:

Code :

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System.setErr( new PrintStream(new ByteArrayOutputStream()));

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Thanks a lot.