code: public void addIgnorePackage(String... packagesToIgnore) {
          if (packagesToIgnore != null && packagesToIgnore.length > 0) {
              final int previousLength = deferPackages.length;
              String[] newDeferPackages = new String[previousLength + packagesToIgnore.length];
              System.arraycopy(deferPackages, 0, newDeferPackages, 0, previousLength);
              System.arraycopy(packagesToIgnore, 0, newDeferPackages, previousLength, packagesToIgnore.length);
              deferPackages = newDeferPackages;
          }
      }
docs: Add packages or classes to ignore. Loading of all classes that locate in the added packages will be delegate to a system classloader.
  <p>
  Package should be specified with using mask. Example:
  </p>
  <pre>
  configuration.addIgnorePackage("org.powermock.example.*");
  </pre>
  
  @param packagesToIgnore fully qualified names of classes or names of packages that end by <code>.*</code>