code: @Nullable
      private KeyType isKeyAccessMethod(int seen) {
          if (seen == Const.INVOKEINTERFACE) {
              String clsName = getClassConstantOperand();
              if (HTTP_SESSION.equals(clsName)) {
                  String methodName = getNameConstantOperand();
                  if (GET_ATTRIBUTE.equals(methodName)) {
                      String signature = getSigConstantOperand();
                      return (GET_ATTRIBUTE_SIG.equals(signature)) ? KeyType.ATTRIBUTE : null;
                  } else if (SET_ATTRIBUTE.equals(methodName)) {
                      String signature = getSigConstantOperand();
                      return (SET_ATTRIBUTE_SIG.equals(signature)) ? KeyType.ATTRIBUTE : null;
                  }
              } else if (HTTP_SERVLET_REQUEST.equals(clsName)) {
                  String methodName = getNameConstantOperand();
                  if (GET_PARAMETER.equals(methodName)) {
                      String signature = getSigConstantOperand();
                      return (GET_PARAMETER_SIG.equals(signature)) ? KeyType.PARAMETER : null;
                  }
              }
          }
  
          return null;
      }
docs: looks to see if this method is a getAttribute/setAttribute on Session or getParameter on HttpServletRequest
  
  @param seen
  the currently parsed opcode
  @return if it is one of these special methods