On 'Save' delete the 'Drawings' object if it is either null or empty

EPPlus/ExcelWorksheet.cs

diff --git a/EPPlus/ExcelWorksheet.cs b/EPPlus/ExcelWorksheet.cs
index 81f5696..2d1371f 100644
--- a/EPPlus/ExcelWorksheet.cs
+++ b/EPPlus/ExcelWorksheet.cs
@@ -2908,7 +2908,7 @@
                         }
 
 
-                        if (Drawings.Count == 0)
+                        if (!HasDrawings() || Drawings.Count == 0)
                         {
                             //Remove node if no drawings exists.
                             DeleteNode("d:drawing");
@@ -4036,6 +4036,12 @@
                 return _drawings;
             }
         }
+
+        public bool HasDrawings()
+        {
+            return (_drawings != null);
+        }
+
         #endregion
         ExcelTableCollection _tables = null;
         /// <summary>

ReadMe_UpdatingEPPlus.txt

diff --git a/ReadMe_UpdatingEPPlus.txt b/ReadMe_UpdatingEPPlus.txt
index 1c7524d..14bf447 100644
--- a/ReadMe_UpdatingEPPlus.txt
+++ b/ReadMe_UpdatingEPPlus.txt
@@ -26,8 +26,8 @@
 2.	Use Git to checkout branch AppSheet.

 3.	Change the appropriate source code files.

 4.	Checkin the changes to Git.

-5.	Build the EPPlus solution.

-6.	Copy the EPPlus.dll and EPPlus.pdb files produced by the build from folder Documents\GitHub\EPPlus\EPPlus\bin\Debug to folder Documents\GitHub\Jeenee\lib.

+5.	Build the EPPlus solution using Visual Studio 2017.

+6.	Copy the EPPlus.dll file produced by the build from folder Documents\GitHub\EPPlus\EPPlus\bin\Debug to folder Documents\GitHub\Jeenee\lib.

 7.	CD to folder Documents\GitHub\Jeenee.

-8.	“git add” the EPPlus.dll and EPPlus.pdb files.

-9.	"git Commit" and "git push" the changes to EPPlus.dll and EPPlus.pdb.

+8.	"git add" the EPPlus.dll file.

+9.	"git Commit" and "git push" the changes to EPPlus.dll.