code: @Override
  	public void sawOpcode(int seen) {
          if ((seen == Const.INVOKEVIRTUAL) && "printStackTrace".equals(getNameConstantOperand())
  				&& SignatureBuilder.SIG_VOID_TO_VOID.equals(getSigConstantOperand())) {
  			bugReporter
  					.reportBug(new BugInstance(this, BugType.IMC_IMMATURE_CLASS_PRINTSTACKTRACE.name(), NORMAL_PRIORITY)
  							.addClass(this).addMethod(this).addSourceLine(this));
  		}
  	}
docs: implements the visitor to check for calls to Throwable.printStackTrace()
  
  @param seen the currently parsed opcode