MTIThreadSafeImageView: when context is nil, skip rendering and report error instead of assert failure.
MTIThreadSafeImageView: when context is nil, skip rendering and report error instead of assert failure.

MetalPetal/MetalPetal,MetalPetal/MetalPetal,MetalPetal/MetalPetal,MetalPetal/MetalPetal,MetalPetal/MetalPetal