AsAnyOptionsOrDollar will convert the given value to AnyOptions.

AsAnyOptionsOrError will convert the given value to AnyOptions.

CastToError will cast the given AnyOptions to error.

Exists return whether the key exists in o.

Get key from o if the key is not found, return nil.

Merge two AnyOptions, return a new merged object override: if there's same key in o and with, whether to override it (make o[key] = with[key]).

RenameDollarKey rename o["$"] to o[to] force: if true, will overwrite the existing o[to] return: same object of o.