def METHOD_NAME(self):
    """
    Checks it has the parameters it needs and tries to send an sms to the users
    that apply.
    """
    if self.url is None:
        return S_ERROR("Slack URL not set")
    # Minor security checks
    element = self.decisionParams["element"]
    if element is None:
        return S_ERROR("element should not be None")
    name = self.decisionParams["name"]
    if name is None:
        return S_ERROR("name should not be None")
    statusType = self.decisionParams["statusType"]
    if statusType is None:
        return S_ERROR("statusType should not be None")
    previousStatus = self.decisionParams["status"]
    if previousStatus is None:
        return S_ERROR("status should not be None")
    status = self.enforcementResult["Status"]
    if status is None:
        return S_ERROR("status should not be None")
    reason = self.enforcementResult["Reason"]
    if reason is None:
        return S_ERROR("reason should not be None")
    if self.decisionParams["element"] == "Site":
        siteName = self.decisionParams["name"]
    else:
        elementType = self.decisionParams["elementType"]
        if elementType == "StorageElement":
            siteName = getSitesForSE(name)
        elif elementType == "ComputingElement":
            res = getCESiteMapping(name)
            if not res["OK"]:
                self.log.error("Failure getting Site2CE mapping", res["Message"])
                siteName = "ERROR"
            else:
                siteName = res
        else:
            siteName = {"OK": True, "Value": "Unassigned"}
        if not siteName["OK"]:
            self.log.error(f"Resource {name} does not exist at any site: {siteName['Message']}")
            siteName = "Unassigned Resources"
        elif not siteName["Value"]:
            siteName = "Unassigned Resources"
        else:
            siteName = siteName["Value"] if isinstance(siteName["Value"], str) else siteName["Value"][0]
    message = f"*{name}* _{statusType}_ --> _{status}_ \n{reason}"
    return self.sendSlackMessage(message)