i want to run custom jql query based on a project (a string parmter which is refrenced) I have selected 

if (project.equals("api")) {
def issues = jiraSearch 'project = api '
def issueString= issues.toString().replaceAll("
[", "").replaceAll("
]", "").replaceAll(",", "\n");
return [issueString]
}

when I run it, the query is not returned,

if I echo the query 

sh "${issueString}"  it is returned

because this does not work it prevents me from using this plugin to show conditional jql query based on our projects, need it to build a ticket from Jira 

general info: 

Jenkins: v2.89.3

running on Ubuntu 17.04

 Operating System: 64bit 

running Jenkins directly**

Your web browser: chrome latest **