Simple test against an code to determine if it falls into the <code>Client Error</code> message category as defined in the <a href="http://tools.ietf.org/html/rfc1945">RFC 1945 - HTTP/1.0</a>, and <a href="http://tools.ietf.org/html/rfc7231">RFC 7231 - HTTP/1.1</a>.
@return true if within range of codes that belongs to <code>Client Error</code> messages.
See Implementation
Simple test against an code to determine if it falls into the <code>Client Error</code> message category as defined in the <a href="http://tools.ietf.org/html/rfc1945">RFC 1945 - HTTP/1.0</a>, and <a href="http://tools.ietf.org/html/rfc7231">RFC 7231 - HTTP/1.1</a>.
@return true if within range of codes that belongs to <code>Client Error</code> messages.