title: Use JSON Input step to process uneven data
body: <p>I'm trying to process the following with an JSON Input step:</p>
  
  <pre class="lang-js prettyprint-override"><code>{"address":[
    {"AddressId":"1_1","Street":"A Street"},
    {"AddressId":"1_101","Street":"Another Street"},
    {"AddressId":"1_102","Street":"One more street", "Locality":"Buenos Aires"},
    {"AddressId":"1_102","Locality":"New York"}
  ]}
  </code></pre>
  
  <p>However this seems not to be possible:</p>
  
  <pre><code>Json Input.0 - ERROR (version 4.2.1-stable, build 15952 from 2011-10-25 15.27.10 by buildguy) : 
  The data structure is not the same inside the resource! 
  We found 1 values for json path [$..Locality], which is different that the number retourned for path [$..Street] (3509 values). 
  We MUST have the same number of values for all paths.
  </code></pre>
  
  <p>The step provides <em>Ignore Missing Path</em> flag but it only works if all the rows misses the same path. In that case that step acts as as expected an fills the missing values with null.</p>
  
  <p>This limits the power of this step to read uneven data, which was really one of my priorities.</p>
  
  <p>My step Fields are defined as follows:</p>
  
  <p><img src="https://i.stack.imgur.com/NcnR5.png" alt="JSON Input Fields definition"></p>
  
  <p>Am I missing something? Is this the correct behavior?</p>