parsing NULLs for double columns is fixed

sql/load.sql

@@ -1,14 +1,3 @@
 IMPORT FROM CSV FILE 'core/demo/sample.csv' INTO sample(usage double, latency
   double, location string, version string);
 
-IMPORT FROM CSV FILE 'core/demo/mobile_data.csv' INTO mobile_data(record_id
- string, user_id string, state string, hw_make string, hw_model string,
-  firmware_version string, app_version string, avg_temp double, battery_drain
-  double, trip_time double);
-
-IMPORT FROM CSV FILE 'wikiticker.csv' INTO wiki(time string, user string, page
-  string, channel string, namespace string, comment string, metroCode string,
-  cityName string, regionName string, regionIsoCode string, countryName string,
-  countryIsoCode string, isAnonymous string, isMinor string, isNew string,
-  isRobot string, isUnpatrolled string, delta double, added double, deleted
-  double);

sql/src/main/java/edu/stanford/futuredata/macrobase/sql/QueryEngine.java

@@ -1,7 +1,6 @@
 package edu.stanford.futuredata.macrobase.sql;
 
 import static com.google.common.collect.ImmutableList.toImmutableList;
-import static java.util.stream.Collectors.toList;
 
 import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
@@ -232,7 +231,7 @@ private List<SingleColumn> removeUDFsInSelect(List<SelectItem> selectItems) {
                 final SingleColumn col = (SingleColumn) item;
                 if (col.getExpression() instanceof FunctionCall) {
                     functionCalls.add(col);
-                     it.remove();
+                    it.remove();
                 }
             }
         }
@@ -341,14 +340,15 @@ private DataFrame getTable(String tableName) throws MacrobaseSQLException {
     }
 
     /**
-     * Evaluate only the UDFs of SQL query and return a Map of column names -> double arrays.
-     * If there are no UDFs (i.e. @param udfCols is empty), the Map is empty.
+     * Evaluate only the UDFs of SQL query and return a Map of column names -> double arrays. If
+     * there are no UDFs (i.e. @param udfCols is empty), an empty Map is returned.
      *
      * @param inputDf The DataFrame to evaluate the UDFs on
      * @param udfCols The List of UDFs to evaluate
      * @return The Map of new columns to be added
      */
-    private Map<String, double[]> evaluateUDFs(final DataFrame inputDf, final List<SingleColumn> udfCols)
+    private Map<String, double[]> evaluateUDFs(final DataFrame inputDf,
+        final List<SingleColumn> udfCols)
         throws MacrobaseException {
         final Map<String, double[]> newColumns = new HashMap<>();
         for (SingleColumn udfCol : udfCols) {

sql/src/main/java/edu/stanford/futuredata/macrobase/sql/tree/SingleColumn.java

@@ -20,7 +20,6 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
-import java.util.stream.Collector;
 
 public class SingleColumn extends SelectItem {
 
@@ -87,8 +86,8 @@ public String toString() {
     }
 
     /**
-     * @return If the Expression is a Function Call (e.g., a UDF), concatenate the function name
-     * and the arguments with "_". Otherwise, return the output of toString()
+     * @return If the Expression is a Function Call (e.g., a UDF), concatenate the function name and
+     * the arguments with "_". Otherwise, return the output of toString()
      */
     private String formatForCol(final Expression expr) {
         if (expr instanceof FunctionCall) {