title: Error when extending FungibleToken: supportedSchemas() in QueryableState clashes with supportedSchemas() in FungibleState
body: <p>I'm using the <strong>Java</strong> template (<code>token-template</code> branch), tokens SDK version is <code>1.1-SNAPSHOT</code>.</p>
  
  <p>I'm extending <code>FungibleToken</code> class to add one extra attribute (<code>PublicKey owningAccount</code>) and I'm getting this error inside Intellij (as red underlines):</p>
  
  <pre><code>supportedSchemas() in QueryableState clashes with supportedSchemas() in FungibleState, attempting to use incompatible type
  </code></pre>
  
  <p>When I add the below function; the compile error is gone (Intellij no longer shows red underlines), but I get a different error on <code>./gradlew deployNodes</code>:</p>
  
  <pre><code>@NotNull
  @Override
  public List&lt;FungibleTokenSchemaV1&gt; supportedSchemas() {
      return super.supportedSchemas();
  }
  </code></pre>
  
  <p>Build error:</p>
  
  <pre><code>&gt; Task :contracts:compileJava FAILED
  MyToken.java:33: error: supportedSchemas() in MyToken cannot implement supportedSchemas() in QueryableState
      public List&lt;FungibleTokenSchemaV1&gt; supportedSchemas() {
                                         ^
    return type List&lt;FungibleTokenSchemaV1&gt; is not compatible with Iterable&lt;MappedSchema&gt;
  1 error
  </code></pre>
  
  <p>Even though <code>List</code> is <code>Iterable</code> and <code>FungibleTokenSchemaV1</code> is <code>MappedSchmea</code>.   </p>
  
  <p>Full code of class:</p>
  
  <pre class="lang-java prettyprint-override"><code>public class MyToken extends FungibleToken {
  
      private final PublicKey owningAccount;
  
      public Shoken(Amount&lt;IssuedTokenType&gt; amount,
                    AbstractParty holder,
                    SecureHash tokenTypeJarHash,
                    PublicKey owningAccount) {
          super(amount, holder, tokenTypeJarHash);
          this.owningAccount = owningAccount;
      }
  
      public PublicKey getOwningAccount() {
          return owningAccount;
      }
  
      @NotNull
      @Override
      public List&lt;FungibleTokenSchemaV1&gt; supportedSchemas() {
          return super.supportedSchemas();
      }
  }
  </code></pre>