.../Drupal/Core/Plugin/PluginWithFormsTrait.php    | 29 ++++++++++++
 .../Drupal/Tests/Core/Block/BlockBaseTest.php      | 35 --------------
 .../Tests/Core/Plugin/PluginWithFormsTraitTest.php | 54 ++++++++++++++++++++++
 3 files changed, 83 insertions(+), 35 deletions(-)

diff --git a/core/lib/Drupal/Core/Plugin/PluginWithFormsTrait.php b/core/lib/Drupal/Core/Plugin/PluginWithFormsTrait.php
new file mode 100644
index 0000000..ce442f0
--- /dev/null
+++ b/core/lib/Drupal/Core/Plugin/PluginWithFormsTrait.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace Drupal\Core\Plugin;
+
+/**
+ * Provides a trait with typical behavior for plugins which have forms.
+ */
+trait PluginWithFormsTrait {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormClass($operation) {
+    if (isset($this->getPluginDefinition()['forms'][$operation])) {
+      return $this->getPluginDefinition()['forms'][$operation];
+    }
+    elseif ($operation === 'configure') {
+      return static::class;
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function hasFormClass($operation) {
+    return !empty($this->getFormClass($operation));
+  }
+
+}
diff --git a/core/tests/Drupal/Tests/Core/Block/BlockBaseTest.php b/core/tests/Drupal/Tests/Core/Block/BlockBaseTest.php
index 0e53b8f..541c0c1 100644
--- a/core/tests/Drupal/Tests/Core/Block/BlockBaseTest.php
+++ b/core/tests/Drupal/Tests/Core/Block/BlockBaseTest.php
@@ -3,7 +3,6 @@
 namespace Drupal\Tests\Core\Block;
 
 use Drupal\block_test\Plugin\Block\TestBlockInstantiation;
-use Drupal\Core\Block\BlockBase;
 use Drupal\Tests\UnitTestCase;
 
 /**
@@ -43,38 +42,4 @@ public function testGetMachineNameSuggestion() {
     $this->assertEquals('uberawesome', $block_base->getMachineNameSuggestion());
   }
 
-  /**
-   * @covers ::getFormClass
-   * @covers ::hasFormClass
-   * @dataProvider providerGetFormClass
-   */
-  public function testGetFormClass(BlockBase $block_plugin, $operation, $expected_class) {
-    $this->assertSame($expected_class, $block_plugin->getFormClass($operation));
-    $this->assertSame($expected_class !== NULL, $block_plugin->hasFormClass($operation));
-  }
-
-  /**
-   * @return array
-   */
-  public function providerGetFormClass() {
-    $block_plugin_without_forms = new TestBlockInstantiation([],  'block_plugin_without_forms', [
-      'provider' => 'block_test',
-    ]);
-    // A block plugin that has a form defined for the 'poke' operation.
-    $block_plugin_with_forms = new TestBlockInstantiation([], 'block_plugin_with_forms', [
-      'provider' => 'block_test',
-      'forms' => [
-        'poke' => static::class,
-      ],
-    ]);
-    return [
-      'block plugin without forms, "configure" operation' => [$block_plugin_without_forms, 'configure', TestBlockInstantiation::class],
-      'block plugin without forms, "tickle" operation'    => [$block_plugin_without_forms, 'tickle', NULL],
-      'block plugin withut forms, "poke" operation'       => [$block_plugin_without_forms, 'poke', NULL],
-      'block plugin with forms, "configure" operation' => [$block_plugin_with_forms, 'configure', TestBlockInstantiation::class],
-      'block plugin with forms, "tickle" operation'    => [$block_plugin_with_forms, 'tickle', NULL],
-      'block plugin with forms, "poke" operation'      => [$block_plugin_with_forms, 'poke', static::class],
-    ];
-  }
-
 }
diff --git a/core/tests/Drupal/Tests/Core/Plugin/PluginWithFormsTraitTest.php b/core/tests/Drupal/Tests/Core/Plugin/PluginWithFormsTraitTest.php
new file mode 100644
index 0000000..2c96e14
--- /dev/null
+++ b/core/tests/Drupal/Tests/Core/Plugin/PluginWithFormsTraitTest.php
@@ -0,0 +1,54 @@
+<?php
+
+namespace Drupal\Tests\Core\Plugin;
+
+use Drupal\Component\Plugin\PluginBase;
+use Drupal\Core\Plugin\PluginWithFormsInterface;
+use Drupal\Core\Plugin\PluginWithFormsTrait;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\Core\Plugin\PluginWithFormsTrait
+ * @group Plugin
+ */
+class PluginWithFormsTraitTest extends UnitTestCase {
+
+  /**
+   * @covers ::getFormClass
+   * @covers ::hasFormClass
+   * @dataProvider providerGetFormClass
+   */
+  public function testGetFormClass(PluginWithFormsInterface $block_plugin, $operation, $expected_class) {
+    $this->assertSame($expected_class, $block_plugin->getFormClass($operation));
+    $this->assertSame($expected_class !== NULL, $block_plugin->hasFormClass($operation));
+  }
+
+  /**
+   * @return array
+   */
+  public function providerGetFormClass() {
+    $block_plugin_without_forms = new TestClass([],  'block_plugin_without_forms', [
+      'provider' => 'block_test',
+    ]);
+    // A block plugin that has a form defined for the 'poke' operation.
+    $block_plugin_with_forms = new TestClass([], 'block_plugin_with_forms', [
+      'provider' => 'block_test',
+      'forms' => [
+        'poke' => static::class,
+      ],
+    ]);
+    return [
+      'block plugin without forms, "configure" operation' => [$block_plugin_without_forms, 'configure', TestClass::class],
+      'block plugin without forms, "tickle" operation'    => [$block_plugin_without_forms, 'tickle', NULL],
+      'block plugin withut forms, "poke" operation'       => [$block_plugin_without_forms, 'poke', NULL],
+      'block plugin with forms, "configure" operation' => [$block_plugin_with_forms, 'configure', TestClass::class],
+      'block plugin with forms, "tickle" operation'    => [$block_plugin_with_forms, 'tickle', NULL],
+      'block plugin with forms, "poke" operation'      => [$block_plugin_with_forms, 'poke', static::class],
+    ];
+  }
+
+}
+
+class TestClass extends PluginBase implements PluginWithFormsInterface {
+  use PluginWithFormsTrait;
+}