private async addCol(fieldName, guid): Promise<any> {
    const digestCache: IDigestCache = this.context.serviceScope.consume(DigestCache.serviceKey);
    digestCache.fetchDigest(this.context.pageContext.web.serverRelativeUrl).then((digest: string): void => {
      let obj = {};

      if (fieldName == "Full Address") {
        obj = "{ '__metadata': { 'type': 'SP.FieldText' }, 'FieldTypeKind': 2,'Title': 'Full Address'}";
      }
      if (fieldName == "Description") {
        obj = "{ '__metadata': { 'type': 'SP.FieldText' }, 'FieldTypeKind': 2,'Title': 'Description' }";
      }
      if (fieldName == "Location") {
        obj = "{ '__metadata': { 'type': 'SP.Field' }, 'FieldTypeKind': 31, 'Title': 'Location' }"
      }
      console.log("Post data: ");
      console.log(obj);

      $.post({
        url: this.context.pageContext.site.serverRelativeUrl + "/_api/web/lists(guid'" + guid + "')/fields",
        type: "POST",
        data: obj,
        headers: {
          "accept": "application/json;odata=verbose",
          "content-type": "application/json;odata=verbose",
          "X-RequestDigest": digest,
        },
        success: function (data) {
          //console.log("done");
          //console.log(data)
          console.log("added: " + fieldName);
        },
        error: function (response) {
          console.log(response.responseText);
        }
      });
    });
  }

{"error":{"code":"-2147023746, Microsoft.SharePoint.SPException","message":{"lang":"en-US","value":"The specified program requires a newer version of Windows. (Exception from HRESULT: 0x8007047E)"}}}