title: how can I sum the values in two maps and return the value using guava
body: <p>How can I sum the values in two maps and return the map with summed values using guava ? It can be safely assumed, both maps will have the same set of keys.</p>
  
  <p>For e.g.:</p>
  
  <pre><code>Map&lt;OccupancyType, BigDecimal&gt; filteredPrice
  [ 1 : 100 ]
  [ 2 : 50 ]
  [ 3 : 200 ]
  </code></pre>
  
  <p>Other map</p>
  
  <pre><code>Map&lt;OccupancyType, BigDecimal&gt; pkgPrice
  [ 1 : 10 ]
  [ 2 : 20 ]
  [ 3 : 30 ]
  </code></pre>
  
  <p>Summed map</p>
  
  <pre><code>Map&lt;OccupancyType, BigDecimal&gt; sumPrice
  [ 1 : 110 ]
  [ 2 : 70 ]
  [ 3 : 230 ]
  </code></pre>
  
  <p>I know I can iterate through these maps and sum the values easily, but is there a cleaner way to do this using one of the guava methods ?</p>