How to change a project's issuetypescreenscheme by groovy

[jingjing]

how to change a project's issuetype screen scheme by groovy.My groovy is below,but when when i run the groovy file, no false information，but not correct.The issuetypescreenscheme disappear

def issueTypeScreenSchemeManager = ComponentAccessor.issueTypeScreenSchemeManager

def issueTypeScreenSchemeObject = issueTypeScreenSchemeManager.getIssueTypeScreenScheme(currentProject)

def currentProject = projectManager.getProjectByCurrentKey("MB6")

IssueTypeScreenScheme myIssueTypeScreenScheme = new IssueTypeScreenSchemeImpl(issueTypeScreenSchemeManager, null);
myIssueTypeScreenScheme.setName(newIssueTypeScreenSchemeName);
myIssueTypeScreenScheme.setDescription(newIssueTypeScreenSchemeName);
myIssueTypeScreenScheme.store();

issueTypeScreenSchemeManager.removeSchemeAssociation(currentProject,issueTypeScreenSchemeObject);
issueTypeScreenSchemeManager.addSchemeAssociation(currentProject,myIssueTypeScreenScheme);