title: How to implement the "or()" method in dius.pact
body: <p>i am writing a pact test and I need a variability.</p>
  
  <p>this is my actual method for defining an price object:</p>
  
  <pre><code>private static LambdaDslObject definePrice(LambdaDslObject object) {
    return object
        .stringType("type") // &lt;--- could be empty or has 2 different values
        .stringType("currencyCode", "EUR")
        .numberType("centAmount")
        .numberType("fractionDigits");
  }
  </code></pre>
  
  <p>but this price object could look like this in JSON:</p>
  
  <p>if type is <code>"centPrecision"</code> or empty:</p>
  
  <pre><code>"value": {
    "type": "centPrecision",
    "currencyCode": "EUR",
    "preciseAmount": 2800,
    "fractionDigits": 2 // &lt;--- is not mandatory in this case
  }
  or
  "value": {
    "currencyCode": "EUR",
    "preciseAmount": 2800,
    "fractionDigits": 2 // &lt;--- is not mandatory in this case
  }
  </code></pre>
  
  <p>or if type is <code>"highPrecision"</code></p>
  
  <pre><code>"value": {
    "type": "highPrecision",
    "currencyCode": "EUR",
    "centAmount": 2800, // &lt;--- is not mandatory in this case
    "preciseAmount": 2800,
    "fractionDigits": 2
  }
  </code></pre>
  
  <p>so I need a distinction according to type of the price.<br>
  I found this <code>or()</code> method but actually don't know how to implement it.<br>
  how can I implement this for pact?</p>