How to extract cookies from messageExchange.getRawRequestData() using groovy?

Question

SOAP

I'm trying to get raw data from this step right in the test step and extract Cookie from it, please help me write a script, now I've only thought of this:
def groovyUtils = new com.eviware.soapui.support.GroovyUtils( context )
def headerValue = messageExchange.getRawRequestData( )
def cookie = headerValue
groovyUtils.setPropertyValue("Properties", "cookie", cookie)
log.info(cookie)
But cookie must be a string...