public TypeBearer pop() {
    throwIfImmutable();

    TypeBearer result = peek(0);

    stack[stackPtr - 1] = null;
    local[stackPtr - 1] = false;
    stackPtr -= result.getType().getCategory();

    return result;
  }
Pops the top element off of the stack.

@return {@code non-null;} the type formerly on the top of the stack
@throws SimException thrown if the stack is empty
android/android_framework/dex-maker/src/main/java/com/android/dx/cf/code/ExecutionStack.java