1. DomName('WebGLRenderingContext.texSubImage2DImage')
  2. DocsEditable()
void texSubImage2DImage(int target, int level, int xoffset, int yoffset, int format, int type, ImageElement image)

Source 

@DomName('WebGLRenderingContext.texSubImage2DImage')
@DocsEditable()
void texSubImage2DImage(int target, int level, int xoffset, int yoffset, int format, int type, ImageElement image) => _blink.BlinkWebGLRenderingContext.instance.texSubImage2D_Callback_7_(unwrap_jso(this), target, level, xoffset, yoffset, format, type, unwrap_jso(image));