         let yearsToAdvance = precess ? Float(yearsSinceEraStart) : nil
         let lines = lineIteratorC(file: fileHandle)
         var count = 0
-        let stars = lines.dropFirst().flatMap { linePtr -> RadialStar? in
+        let stars = lines.dropFirst().compactMap { linePtr -> RadialStar? in
             defer { free(linePtr) }
             return RadialStar(rowPtr :linePtr, advanceByYears: yearsToAdvance, indexers: &indexers)
         }

    }
    
    public static func save<T: CSVWritable>(stars: [T], to path: String) throws {
        let lines = [T.headerLine] + stars.flatMap({ $0.csvLine })
        let fileString = lines.joined(separator: "\n")
        try fileString.write(to: URL(fileURLWithPath: path), atomically: true, encoding: .utf8)
    }

        let yearsToAdvance = precess ? Double(yearsSinceEraStart) : nil
        let lines = lineIteratorC(file: fileHandle)
        var count = 0
        let stars = lines.dropFirst().compactMap { linePtr -> Star3D? in
            defer { free(linePtr) }
            return Star3D(rowPtr :linePtr, advanceByYears: yearsToAdvance, indexers: &indexers)
        }
