How can I get a custom epik field with a link to it ?
import com.atlassian.jira.issue.Issue
import com.atlassian.jira.issue.ModifiedValue
import com.atlassian.jira.issue.util.DefaultIssueChangeHolder
import com.atlassian.jira.component.ComponentAccessor
def customFieldManager = ComponentAccessor.getCustomFieldManager()
def epicLinkCf = customFieldManager.getCustomFieldObjectByName("Epic Link")
def epicIssue = issue.getCustomFieldValue(epicLinkCf) as Issue
def epicCustomField = customFieldManager.getCustomFieldObjectByName("Rank")
def textCf2 = customFieldManager.getCustomFieldObjects(issue).find {it.name == "EpicRank"}
if (textCf2) {
def changeHolder = new DefaultIssueChangeHolder()
textCf2.updateValue(null, issue, new ModifiedValue(issue.getCustomFieldValue(textCf2), issue.getCustomFieldValue(epicLinkCf).toString()),changeHolder)
}