Fatal error: Cannot redeclare class Stripe\Util\Set

function stripe_admin(){

  if(is_user_logged_in()){

    $user_id = get_current_user_id();

    if ($user_id == 1){

      global $stripe_options;

        // load the stripe libraries
        if ( !class_exists( 'Stripe' ) )
          require(dirname(__DIR__).'/libraries/stripe-php/init.php');

        // check if we are using test mode
        if ( isset( $stripe_options['test_mode'] ) && $stripe_options['test_mode'] ) {
          $secret_key = trim( $stripe_options['test_secret_key'] );
        } else {
          $secret_key = trim( $stripe_options['live_secret_key'] );
        }

        \Stripe\Stripe::setApiKey( $secret_key );

        $customers = \Stripe\Customer::all();
        /*
        ?>

        <h2>Payers</h2>

        <table class="stripe-admin-table" id="payerTable">
         <thead>
          <tr>
            <th>Name</th>
            <th>Email</th>
            <th>Phone</th>
          </tr>
          </thead>
          <tbody>
          <?php foreach($payers as $payer){ ?>

          <tr>
            <td><?php echo $payer->name; ?></td>
            <td><?php echo $payer->email; ?></td>
            <td><?php echo $payer->phone; ?></td>
          </tr>

          <?php } ?>
          </tbody>
        </table>
        */ ?>
        <h2>Stripe Customers</h2>

        <table class="stripe-admin-table" id="myTable">
         <thead>
          <tr>
            <th>Name</th>
            <th>Email</th>
            <th>Plan</th>
            <th>Payer</th>
            <th>Premium</th>
            <th>Delinquent</th>
            <th>Customer Created</th>
          </tr>
          </thead>
          <tbody>
          <?php foreach($customers->data as $cus){ ?>

          <tr>
            <td><a href="https://dashboard.stripe.com/test/customers/<?php echo $cus->id; ?>" target="_BLANK"><?php echo $cus->metadata->name; ?></a></td>
            <td><?php echo $cus->email; ?></td>
            <td><?php echo $cus->subscriptions->data[0]['plan']['name']; ?></td>
            <td><?php echo $cus->metadata->payer; ?></td>
            <td><?php echo $cus->metadata->premium; ?></td>
            <td <?php if($cus->delinquent){ echo 'style="color:red;"'; }?>><?php if($cus->delinquent){echo 'YES';}else{echo 'NO';} ?></td>
            <td><?php echo date_i18n('m-d-y',$cus->created); ?></td>
          </tr>

          <?php } ?>
          </tbody>
        </table>

        <?php

    }else{
      wp_redirect('http://gacdev.amsvps12.com/new-subscriber'); exit;
    }
  }else{
    wp_redirect('http://gacdev.amsvps12.com/new-subscriber'); exit;
  }

}
add_shortcode('stripe-admin', 'stripe_admin');