@API(status = API.Status.STABLE)
    public boolean contains(final @NonNull String name) {
        return this.hasFlag(name);
    }
Check whether a flag is present. This will return {@code true} if the flag
is a presence flag and is present, or if the flag is a value flag and has
a value provided.

@param name Flag name
@return whether the flag is present
cloud-core/src/main/java/org/incendo/cloud/parser/flag/FlagContext.java