IsB64ContentType checks that a set of path.Expression, including the attribute the validator is applied to, is a valid base64 encoded string that is one of the specified content types.

IsBase64Encoded checks if a string is base64 encdoed.

IsRequiredIfMatchesPathValue validates if the provided string value equals the value at the provided path expression(s).

IsRequiredIfRegexMatchesPathValue validates if the provided regex matches the value at the provided path expression(s).

RegexMatchesPathValue validates if the provided regex matches the value at the provided path expression(s).

ShouldNotContain checks that the String held in the attribute is none of the given `values`.