jodd-proxetta/src/main/java/jodd/asm7/MethodWriter.java
int visitFrameStart(final int offset, final int numLocal, final int numStack) {
    int frameLength = 3 + numLocal + numStack;
    if (currentFrame == null || currentFrame.length < frameLength) {
      currentFrame = new int[frameLength];
    }
    currentFrame[0] = offset;
    currentFrame[1] = numLocal;
    currentFrame[2] = numStack;
    return 3;
  }
int visitFrameStart(final int offset, final int numLocal, final int numStack) {
    int frameLength = 3 + numLocal + numStack;
    if (currentFrame == null || currentFrame.length < frameLength) {
      currentFrame = new int[frameLength];
    }
    currentFrame[0] = offset;
    currentFrame[1] = numLocal;
    currentFrame[2] = numStack;
    return 3;
  }
Starts the visit of a new stack map frame, stored in {@link #currentFrame}.

@param offset the bytecode offset of the instruction to which the frame corresponds.
@param numLocal the number of local variables in the frame.
@param numStack the number of stack elements in the frame.
@return the index of the next element to be written in this frame.