question: protected < T > Database makeSimpleDatabase ( String filename , int expectedSize , ListParameterization params , Class < ? > [ ] filters ) { try ( InputStream is = open ( filename ) ) { List < ObjectFilter > filterlist = new ArrayList < > ( ) ; filterlist . add ( new FixedDBIDsFilter ( 1 ) ) ; if ( filters != null ) { for ( Class < ? > filtercls : filters ) { ObjectFilter filter = ClassGenericsUtil . parameterizeOrAbort ( filtercls , params ) ; filterlist . add ( filter ) ; } } NumberVectorLabelParser < DoubleVector > parser = new NumberVectorLabelParser < > ( DoubleVector . FACTORY ) ; InputStreamDatabaseConnection dbc = new InputStreamDatabaseConnection ( is , filterlist , parser ) ; params . addParameter ( AbstractDatabase . Parameterizer . DATABASE_CONNECTION_ID , dbc ) ; Database db = ClassGenericsUtil . parameterizeOrAbort ( StaticArrayDatabase . class , params ) ; testParameterizationOk ( params ) ; db . initialize ( ) ; Relation < ? > rel = db . getRelation ( TypeUtil . ANY ) ; assertEquals ( "Database size does not match." , expectedSize , rel . size ( ) ) ; return db ; } catch ( IOException e ) { fail ( "Test data " + filename + " not found." ) ; return null ; } }
target:  Generate a simple DoubleVector database from a file.