Reports incorrect <lookup-method> for a bean in XML application contexts.

Example:

  public abstract class FooLookupBean {
    protected abstract FooBean createCommand();
    private FooBean createCommand() {...}
    protected static FooBean createCommandStatic() {...}
    protected abstract FooBean createWithArgs(String foo);
    protected abstract OtherBean createOtherBean();
  }

  <beans>
    <bean class="FooLookupBean" id="lookupTest">
      <lookup-method bean="fooBean" name="createCommand"/>
      <!-- private -->
      <lookup-method bean="fooBean" name="createCommand"/>// "Method must be public or protected"
      <!-- static -->
      <lookup-method bean="fooBean" name="createCommandStatic"/> // Static method not allowed here
      <!-- with arguments -->
      <lookup-method bean="fooBean" name="createWithArgs"/>// Method must have no parameters
      <!-- not exist -->
      <lookup-method bean="fooBean" name="unknown"/>  // unknown method
      <!-- mismatch -->
      <lookup-method bean="fooBean" name="createOtherBean"/> // Lookup method return type does not match the 'FooBean' bean class
    </bean>

    <bean class="FooBean" id="fooBean"/>
    <bean class="OtherBean" id="otherBean"/>
  </beans>