code: public ApnsClientBuilder setClientCredentials(final File p12File, final String p12Password) throws SSLException, IOException {
          try (final InputStream p12InputStream = new FileInputStream(p12File)) {
              return this.setClientCredentials(p12InputStream, p12Password);
          }
      }
docs: <p>Sets the TLS credentials for the client under construction using the contents of the given PKCS#12 file.
  Clients constructed with TLS credentials will use TLS-based authentication when sending push notifications. The
  PKCS#12 file <em>must</em> contain a certificate/private key pair.</p>
  
  <p>Clients may not have both TLS credentials and a signing key.</p>
  
  @param p12File a PKCS#12-formatted file containing the certificate and private key to be used to identify the
  client to the APNs server
  @param p12Password the password to be used to decrypt the contents of the given PKCS#12 file; passwords may be
  blank (i.e. {@code ""}), but must not be {@code null}
  
  @throws SSLException if the given PKCS#12 file could not be loaded or if any other SSL-related problem arises
  when constructing the context
  @throws IOException if any IO problem occurred while attempting to read the given PKCS#12 file, or the PKCS#12
  file could not be found
  
  @return a reference to this builder
  
  @since 0.8