title: Spring Boot: The method add(Converter) in the type Set<Converter> is not applicable for the arguments (...)
body: <p>When trying to add something to the converters HashSet in ConversionConfig.java, I get the following error in RED:</p>
  <p><strong>Error:</strong></p>
  <pre><code>The method add(Converter) in the type Set&lt;Converter&gt; is not applicable for the arguments (RoomEntityToReservationResponseConverter)
  </code></pre>
  <p><strong>ConversionConfig.java:</strong></p>
  <pre class="lang-java prettyprint-override"><code>      @Configuration 
          public class ConversionConfig {
          
              @SuppressWarnings(&quot;rawtypes&quot;)
              private Set&lt;Converter&gt; getConverters() {
                      Set&lt;Converter&gt; converters = new HashSet&lt;Converter&gt;();
                      converters.add(new RoomEntityToReservationResponseConverter());
          
                      return converters;
              }
          
              @Bean public ConversionService conversionService() {
                      ConversionServiceFactoryBean bean = new ConversionServiceFactoryBean();
                      bean.setConverters(getConverters());
                      bean.afterPropertiesSet();
          
                      return bean.getObject();
              }
          }
  </code></pre>
  <p><strong>RoomEntityToReservationResponseConverter.java:</strong></p>
  <pre class="lang-java prettyprint-override"><code>    public class RoomEntityToReservationResponseConverter implements Converter&lt;RoomEntity, ReservationResponse&gt;{
      
          @Override
          public ReservationResponse convert(RoomEntity source) {
              
              ReservationResponse reservationResponse = new ReservationResponse();
              reservationResponse.setRoomNumber(source.getRoomNumber());
              reservationResponse.setPrice( Integer.valueOf(source.getPrice()) );
              
              Links links = new Links();
              Self self = new Self();
              self.setRef(ResourceConstants.ROOM_RESERVATION_V1 + &quot;/&quot; + source.getId());
              links.setSelf(self);
              
              reservationResponse.setLinks(links);
              
              return reservationResponse;
          }
      
          
          
      }
  </code></pre>
  <p>Not sure what is going on - I am new to Spring Boot. Looking at similar questions has not helped, because I don't understand the root problem, if someone could spell out the solution using code from this particular instance, that would be helpful to get a better idea.</p>