Update to return reader

src/main/java/gov/usgs/earthquake/nshmp/netcdf/Netcdf.java

@@ -11,6 +11,7 @@ import gov.usgs.earthquake.nshmp.netcdf.data.BoundingData;
 import gov.usgs.earthquake.nshmp.netcdf.data.NetcdfData;
 import gov.usgs.earthquake.nshmp.netcdf.data.NetcdfShape;
 import gov.usgs.earthquake.nshmp.netcdf.data.StaticData;
+import gov.usgs.earthquake.nshmp.netcdf.reader.Reader;
 
 /**
  * Abstarct class for NetCDF types: hazard curves and ground motions.
@@ -39,8 +40,9 @@ public abstract class Netcdf<T> {
     }
 
     dataType = NetcdfDataType.getDataType(netcdfPath);
-    netcdfData = getNetcdfData(netcdfPath);
-    netcdfShape = buildNetcdfShape();
+    var reader = getNetcdfData(netcdfPath);
+    netcdfData = reader.netcdfData();
+    netcdfShape = reader.netcdfShape();
   }
 
   /**
@@ -91,7 +93,5 @@ public abstract class Netcdf<T> {
    */
   public abstract T staticData(Location site, NehrpSiteClass siteClass);
 
-  abstract NetcdfShape buildNetcdfShape();
-
-  abstract NetcdfData getNetcdfData(Path netcdfPath);
+  abstract Reader getNetcdfData(Path netcdfPath);
 }