code: private String readInstrumentationKeyFromConfiguration() {
          try (final InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream(
              CONFIGURATION_FILE)) {
              final String configuration = IOUtils.toString(inputStream);
              final Matcher matcher = INSTRUMENTATION_KEY_PATTERN.matcher(configuration);
              if (matcher.find()) {
                  return matcher.group(1);
              } else {
                  return StringUtils.EMPTY;
              }
          } catch (IOException exception) {
              return StringUtils.EMPTY;
          }
      }
docs: Get instrumentation key from ApplicationInsights.xml