Jenkins extract commit from comment

jenkins.groovy

def thr = Thread.currentThread()
def build = thr?.executable
def env = build.getBuildVariables()
//def env = build.getEnvironment()

println env
def ghprbCommentBody = env.get("ghprbCommentBody")
println "ghprbCommentBody=$ghprbCommentBody"


def map = [BACKEND_TARGET_BRANCH: "refs/remotes/origin/master"]

def match = (ghprbCommentBody =~ /jenkins retest this please against ([0-9a-zA-Z]+)/)

if (match) {
    map = [BACKEND_TARGET_BRANCH: match[0][1]]
}

println map
return map