feat: remove unused getPlainForeignKey

Author: divine

src/Relations/HasMany.php

@@ -17,15 +17,6 @@ public function getForeignKeyName()
         return $this->foreignKey;
     }
 
-    /**
-     * Get the plain foreign key.
-     * @return string
-     */
-    public function getPlainForeignKey()
-    {
-        return $this->getForeignKeyName();
-    }
-
     /**
      * Get the key for comparing against the parent key in "has" query.
      * @return string

src/Relations/HasOne.php

@@ -26,15 +26,6 @@ public function getHasCompareKey()
         return $this->getForeignKeyName();
     }
 
-    /**
-     * Get the plain foreign key.
-     * @return string
-     */
-    public function getPlainForeignKey()
-    {
-        return $this->getForeignKeyName();
-    }
-
     /**
      * @inheritdoc
      */