@Pure
	public String getInternalId() {
		final int endIndex = this.id.indexOf('#');
		if (endIndex <= 0) {
			return null;
		}
		return this.id.substring(0, endIndex);
	}
@ Pure public String getInternalId ( ) { final int endIndex = this . id . indexOf ( '#' ) ; if ( endIndex <= 0 ) { return null ; } return this . id . substring ( 0 , endIndex ) ; }
Extract the unique identifier stored in this geoId.

@return the internal identifier or <code>null</code> if this
geoid has invalid format.