code: @Deprecated
      protected Map<String, Object> flattenResults(final Map<String, List<Object>> multivaluedUserAttributes) {
          if (!this.enabled) {
              return null;
          }
  
          if (multivaluedUserAttributes == null) {
              return null;
          }
  
          //Convert the <String, List<Object> results map to a <String, Object> map using the first value of each List
          final Map<String, Object> userAttributes = new LinkedHashMap<>(multivaluedUserAttributes.size());
  
          for (final Map.Entry<String, List<Object>> attrEntry : multivaluedUserAttributes.entrySet()) {
              final String attrName = attrEntry.getKey();
              final List<Object> attrValues = attrEntry.getValue();
  
              final Object value;
              if (attrValues == null || attrValues.size() == 0) {
                  value = null;
              } else {
                  value = attrValues.get(0);
              }
  
              userAttributes.put(attrName, value);
          }
  
          logger.debug("Flattened Map='{}' into Map='{}'", multivaluedUserAttributes, userAttributes);
  
          return userAttributes;
      }
docs: Takes a &lt;String, List&lt;Object&gt;&gt; Map and coverts it to a &lt;String, Object&gt; Map. This implementation takes
  the first value of each List to use as the value for the new Map.
  
  @param multivaluedUserAttributes The attribute map to flatten.
  @return A flattened version of the Map, null if the argument was null.
  @deprecated This method is just used internally and will be removed with this class in 1.6