title: JSON filtering attributes
body: <p>What is the best way to filter JSON nested keys and delete them? For example:</p>
  
  <pre><code>{ "id"    : "1",
    "key1"  : "val1",
    "key2"  : "val2",
    "name"  : "someone",
    "age"   : 39,
    "data"  : [
      { "id"    : "1234",
        "key1"  : "val1",
        "key2"  : "val2",
        "name"  : "someone",
        "age"   : 39
      },
      { "id"    : "1234",
        "key1"  : "val1",
        "key2"  : "val2",
        "name"  : "someone",
        "age"   : 39
      }
    ]
  }
  </code></pre>
  
  <p>To get the following JSON by deleting all <code>key1</code> and <code>key2</code> items recursively:</p>
  
  <pre><code>{ "id"    : "1",
    "name"  : "someone",
    "age"   : 39,
    "data"  : [
      { "id"    : "1234",
        "name"  : "someone",
        "age"   : 39
      },
      { "id"    : "1234",
        "name"  : "someone",
        "age"   : 39
      }
    ] 
  }
  </code></pre>
  
  <p>Thanks.</p>