TypeScript helper methods related to use of PnP Taxonomy Picker SPFx React control.

PnPJS_TaxonomyPickerHelperMethods.ts

// used to get object suitable for writing a single-valued taxonomy value to SharePoint from the PnP taxonomy picker control..
private static getTaxonomyTerm(termDetails: IPickerTerm): ITaxonomyTerm {
    let taxonomyTerm: ITaxonomyTerm;

    if (termDetails) {
      taxonomyTerm = {
        TermGuid: termDetails.key,
        Label: termDetails.name,
        WssId: -1
      };
    }

    return taxonomyTerm;
}

// used to get object suitable for setting current value of PnP taxonomy picker control from data fetched from SharePoint..
private static getPickerTerm(retrievedTaxValue: ITaxonomyTerm, taxCatchAll: Array<any>): IPickerTerm {
    let pickerTerm: IPickerTerm;

    if (retrievedTaxValue) {
      if (taxCatchAll && taxCatchAll.length > 0 && retrievedTaxValue) {
        const result = taxCatchAll.filter(item => item.ID === retrievedTaxValue.WssId);
        if (result.length === 1) {
          pickerTerm = {
            name: result[0].Term,
            path: result[0].Term,
            key: retrievedTaxValue.TermGuid,
            termSet: undefined,
            termSetName: undefined
          };
        } else {
          console.warn("setTaxonomyTerm: WARNING! Unable to load value for field: " + retrievedTaxValue.Label);
          console.warn({ taxCatchAll });
        }
      }
    }

    return pickerTerm;
  }

How do you get TermGuid from taxCatchAll?