commons/http/src/main/java/org/ldp4j/http/ImmutableMediaType.java
private static void checkQuotedString(final String quotedString) {
		boolean quotedPair=false;
		for(int i=0;i<quotedString.length();i++) {
			final char ch=quotedString.charAt(i);
			if(quotedPair) {
				checkArgument(QUOTED_PAIR.get(ch),"Invalid quoted-pair character '%s' in quoted string '%s' at %d",ch,quotedString ,i);
				quotedPair=false;
			} else if(ch==SLASH) {
				quotedPair=true;
			} else {
				checkArgument(QDTEXT.get(ch),"Invalid character '%s' in quoted string '%s' at %d",ch,quotedString ,i);
			}

		}
		checkArgument(!quotedPair,"Missing quoted-pair character in quoted string '%s' at %d",quotedString,quotedString.length());
	}
private static void checkQuotedString(final String quotedString) {
		boolean quotedPair=false;
		for(int i=0;i<quotedString.length();i++) {
			final char ch=quotedString.charAt(i);
			if(quotedPair) {
				checkArgument(QUOTED_PAIR.get(ch),"Invalid quoted-pair character '%s' in quoted string '%s' at %d",ch,quotedString ,i);
				quotedPair=false;
			} else if(ch==SLASH) {
				quotedPair=true;
			} else {
				checkArgument(QDTEXT.get(ch),"Invalid character '%s' in quoted string '%s' at %d",ch,quotedString ,i);
			}

		}
		checkArgument(!quotedPair,"Missing quoted-pair character in quoted string '%s' at %d",quotedString,quotedString.length());
	}
Checks the given quoted string for illegal characters, as defined in RFC
7230, section 3.2.6.

@throws IllegalArgumentException
in case of illegal characters
@see <a href="http://tools.ietf.org/html/rfc7230#section-3.2.6">Hypertext
Transfer Protocol (HTTP/1.1): Message Syntax and Routing, Section
3.2.6</a>