code: private boolean isOgmImplicitEnabled(Map<?, ?> settings) {
  		String jdbcUrl = new ConfigurationPropertyReader( settings )
  				.property( Environment.URL, String.class )
  				.getValue();
  
  		String jndiDatasource = new ConfigurationPropertyReader( settings )
  				.property( Environment.DATASOURCE, String.class )
  				.getValue();
  
  		String dialect = new ConfigurationPropertyReader( settings )
  				.property( Environment.DIALECT, String.class )
  				.getValue();
  
  		return jdbcUrl == null && jndiDatasource == null && dialect == null;
  	}
docs: Decides if we need to start OGM when {@link OgmProperties#ENABLED} is not set.
  At the moment, if a dialect class is not declared, Hibernate ORM requires a datasource or a JDBC connector when a dialect is not declared.
  If none of those properties are declared, we assume the user wants to start Hibernate OGM.
  
  @param settings
  @return {@code true} if we have to start OGM, {@code false} otherwise