XBRL Item – Ex-101.INS-XBRL Instance Document - nick-20220331_htm.xml -

XBRL Item – Ex-101.SCH-XBRL Taxonomy Extension Schema Document - nick-20220331.xsd -

XBRL Item – Ex-101.CAL-XBRL Taxonomy Extension Calculation Linkbase Document - nick-20220331_cal.xml -

XBRL Item – Ex-101.LAB-XBRL Taxonomy Extension Label Linkbase Document - nick-20220331_lab.xml -

XBRL Item – Ex-101.PRE-XBRL Taxonomy Extension Presentation Linkbase Document - nick-20220331_pre.xml -

XBRL Item – Ex-101.DEF-XBRL Taxonomy Extension Definition Linkbase Document - nick-20220331_def.xml -

XBRL Item – Ex-101.INS-XBRL Instance Document - nick-20211231.xml -

XBRL Item – Ex-101.SCH-XBRL Taxonomy Extension Schema Document - nick-20211231.xsd -

XBRL Item – Ex-101.CAL-XBRL Taxonomy Extension Calculation Linkbase Document - nick-20211231_cal.xml -

XBRL Item – Ex-101.LAB-XBRL Taxonomy Extension Label Linkbase Document - nick-20211231_lab.xml -

XBRL Item – Ex-101.PRE-XBRL Taxonomy Extension Presentation Linkbase Document - nick-20211231_pre.xml -

XBRL Item – Ex-101.DEF-XBRL Taxonomy Extension Definition Linkbase Document - nick-20211231_def.xml -

XBRL Item – Ex-101.INS-XBRL Instance Document - nick-20210930.xml -

XBRL Item – Ex-101.SCH-XBRL Taxonomy Extension Schema Document - nick-20210930.xsd -

XBRL Item – Ex-101.CAL-XBRL Taxonomy Extension Calculation Linkbase Document - nick-20210930_cal.xml -

XBRL Item – Ex-101.LAB-XBRL Taxonomy Extension Label Linkbase Document - nick-20210930_lab.xml -

XBRL Item – Ex-101.PRE-XBRL Taxonomy Extension Presentation Linkbase Document - nick-20210930_pre.xml -

XBRL Item – Ex-101.DEF-XBRL Taxonomy Extension Definition Linkbase Document - nick-20210930_def.xml -

XBRL Item – Ex-101.INS-XBRL Instance Document - nick-20210630.xml -

XBRL Item – Ex-101.SCH-XBRL Taxonomy Extension Schema Document - nick-20210630.xsd -

XBRL Item – Ex-101.CAL-XBRL Taxonomy Extension Calculation Linkbase Document - nick-20210630_cal.xml -

XBRL Item – Ex-101.LAB-XBRL Taxonomy Extension Label Linkbase Document - nick-20210630_lab.xml -

XBRL Item – Ex-101.PRE-XBRL Taxonomy Extension Presentation Linkbase Document - nick-20210630_pre.xml -

XBRL Item – Ex-101.DEF-XBRL Taxonomy Extension Definition Linkbase Document - nick-20210630_def.xml -