public MetadataConverterIF getMetadataConverter(String key) {
    if (key == null) return null;
    return metadataConverters.get(key);
  }
public MetadataConverterIF getMetadataConverter(String key) {
    if (key == null) return null;
    return metadataConverters.get(key);
  }
public MetadataConverterIF getMetadataConverter ( String key ) { if ( key == null ) return null ; return metadataConverters . get ( key ) ; }
Find the MetadataConverterIF registered for this key
@param key search on this key
@return  MetadataConverterIF else null
Find the MetadataConverterIF registered for this key