title: "Lambda with Receiver": What is this Kotlin construct?
body: <p>I'm looking at this Kotlin object declaration:</p>
  
  <pre><code>object A : B({
      variableName1 = "text1"
      variableName2 = "text2"
  
      params {
          param("Foo", "Bar")
      }
  })
  </code></pre>
  
  <p>And I cannot figure out what the argument to class B's constructor is.</p>
  
  <p>I have purposefully abstracted away information in this example but class B is actually</p>
  
  <pre><code>jetbrains.buildServer.configs.kotlin.v10.BuildType
  </code></pre>
  
  <p>And I cannot find the documentation for the type. <a href="http://javadoc.jetbrains.net/teamcity/openapi/10.0/" rel="noreferrer">I have found something that was close</a> but it's a definition for an interface and thus doesn't have a constructor. </p>
  
  <p>To summarise, what is this the following construct in Kotlin?</p>
  
  <pre><code>{
      variableName1 = "text1"
      variableName2 = "text2"
  
      params {
          param("Foo", "Bar")
      }
  }
  </code></pre>