ERROR: MixedAnyArrayAccess - input.hack:3:10 - Unsafe array access on value with type any
ERROR: MixedAnyArrayAccess - input.hack:4:10 - Unsafe array access on value with type nonnull-from-any
ERROR: MixedAnyArgument - input.hack:4:10 - Argument 1 of echo expects ?scalar, any provided
ERROR: MixedAnyReturnStatement - input.hack:5:12 - Could not infer a proper return type — saw nonnull-from-any