Field.php

1. 8.x drupal/core/modules/field/lib/Drupal/field/Field.php
2. 8.x drupal/core/lib/Drupal/Core/Entity/Field/Type/Field.php
3. 8.x drupal/core/modules/field/lib/Drupal/field/Plugin/views/field/Field.php
4. 8.x drupal/core/modules/field/lib/Drupal/field/Plugin/Core/Entity/Field.php

<?php

/**
 * @file
 * Contains \Drupal\field\Field.
 */
namespace Drupal\field;

use Drupal;

/**
 * Static service container wrapper for Field.
 */
class Field {

  /**
   * Returns the field info service.
   *
   * @return \Drupal\field\FieldInfo
   *   Returns a field info object.
   */
  public static function fieldInfo() {
    return Drupal::service('field.info');
  }

}