docs: public static FieldAnnotation isRead(Instruction ins, ConstantPoolGen cpg) {
          if (ins instanceof GETFIELD || ins instanceof GETSTATIC) {
              FieldInstruction fins = (FieldInstruction) ins;
              String className = fins.getClassName(cpg);
              return new FieldAnnotation(className, fins.getName(cpg), fins.getSignature(cpg), fins instanceof GETSTATIC);
          } else {
              return null;
          }
      }