question: public void addNativeChildAt ( ReactShadowNode child , int nativeIndex ) { Assertions . assertCondition ( ! mIsLayoutOnly ) ; Assertions . assertCondition ( ! child . mIsLayoutOnly ) ; if ( mNativeChildren == null ) { mNativeChildren = new ArrayList < > ( 4 ) ; } mNativeChildren . add ( nativeIndex , child ) ; child . mNativeParent = this ; }
target:  Adds a child that the native view hierarchy will have at this index in the native view corresponding to this node.