question: public Sensor createNewSensor ( String systemName , String userName ) { Sensor s ; String sName = AcelaAddress . normalizeSystemName ( systemName ) ; if ( sName . equals ( "" ) ) { log . error ( "Invalid Acela Sensor system name: " + systemName ) ; return null ; } s = getBySystemName ( sName ) ; if ( s != null ) { log . error ( "Sensor with this name already exists: " + systemName ) ; return null ; } String altName = AcelaAddress . convertSystemNameToAlternate ( sName ) ; s = getBySystemName ( altName ) ; if ( s != null ) { log . error ( "Sensor with name: '" + systemName + "' already exists as: '" + altName + "'" ) ; return null ; } int bit = AcelaAddress . getBitFromSystemName ( sName ) ; if ( ( bit < 0 ) || ( bit >= 1023 ) ) { log . error ( "Sensor bit number: " + Integer . toString ( bit ) + ", is outside the supported range, 1-1024" ) ; return null ; } if ( userName == null ) { s = new AcelaSensor ( sName ) ; } else { s = new AcelaSensor ( sName , userName ) ; } AcelaNode node = AcelaAddress . getNodeFromSystemName ( sName , _memo ) ; if ( node == null ) { log . warn ( "Sensor: " + sName + ", refers to an undefined Acela Node." ) ; return s ; } if ( ! node . hasActiveSensors ) { int newnodeaddress ; newnodeaddress = node . getNodeAddress ( ) ; log . warn ( "We got the wrong node: " + newnodeaddress ) ; return s ; } node . registerSensor ( s , bit ) ; return s ; }
target:  Create a new sensor if all checks are passed System name is normalized to ensure uniqueness.