question: public static DataType lookupForField ( Element variableElement , Messager messager , Types types ) { Element fieldTypeElement = types . asElement ( variableElement . asType ( ) ) ; boolean isTypeElement = false ; if ( fieldTypeElement instanceof TypeElement ) { isTypeElement = true ; TypeElement typeElement = ( TypeElement ) fieldTypeElement ; TypeMirror superclass = typeElement . getSuperclass ( ) ; if ( superclass instanceof DeclaredType ) { DeclaredType superclassDeclaredType = ( DeclaredType ) superclass ; if ( JAVA_LANG_ENUM . equals ( getCanonicalTypeName ( superclassDeclaredType ) ) ) { return DataType . ENUM_STRING ; } } } String fieldClassName = findFieldClassname ( variableElement ) ; DataType dataType = builtInMap . get ( fieldClassName ) ; if ( dataType != null ) { return dataType ; } throw new RuntimeException ( "Couldn't find data type for " + fieldClassName + "/" + variableElement . getKind ( ) + "/isTypeElement: " + isTypeElement ) ; }
target:  Lookup the data-type associated with the class.