private void completeVariable(Editor editor) {
    String prefix = this.myNameSuggestionsField.getEnteredName();
    PsiReference reference = this.myTag.getReference();
    if(reference instanceof TagNameReference) {
        LookupElement[] lookupItems = TagNameReferenceCompletionProvider.getTagNameVariants(this.myTag, this.myTag.getNamespacePrefix());
        editor.getCaretModel().moveToOffset(prefix.length());
        editor.getSelectionModel().removeSelection();
        LookupManager.getInstance(this.getProject()).showLookup(editor, lookupItems, prefix);
    }

}
 

public TagNameReference createTagNameReference(final ASTNode nameElement, final boolean startTagFlag) {
    return new BPMNTagNameReference(nameElement, startTagFlag);
}