code: function getHeaderParameterValue(sHeaderValue, sParameterName) {
  		var iParamIndex,
  			aHeaderParts = sHeaderValue.split(";"),
  			aMatches;
  
  		sParameterName = sParameterName.toLowerCase();
  		for (iParamIndex = 1; iParamIndex < aHeaderParts.length; iParamIndex += 1) {
  			// remove possible quotes via reg exp
  			// RFC7231: parameter = token "=" ( token / quoted-string )
  			aMatches = rHeaderParameter.exec(aHeaderParts[iParamIndex]);
  			if (aMatches[1].toLowerCase() === sParameterName) {
  				return aMatches[2] || aMatches[3];
  			}
  		}
  	}
docs: Extracts value of the parameter with the specified <code>sParameterName</code>
  from the specified <code>sHeaderValue</code>.
  
  @param {string} sHeaderValue
  HTTP header value e.g. "application/json;charset=utf-8"
  @param {string} sParameterName
  Name of HTTP header parameter e.g. "charset"
  @returns {string} The HTTP header parameter value