oops, fix test which broke when cleaning up PR

Author: xzackli

src/IJulia.jl

@@ -38,7 +38,7 @@ import Base.invokelatest
 import Dates
 using Dates: now
 import Random
-using Base64: Base64EncodePipe
+using Base64: Base64EncodePipe, base64decode
 import REPL
 
 # InteractiveUtils is not used inside IJulia, but loaded in src/kernel.jl

test/inline.jl

@@ -1,5 +1,5 @@
 using Test
-import IJulia: InlineIOContext
+import IJulia: InlineIOContext, png_wh
 
 @testset "Custom Jupyter inline display" begin
     @eval struct TestDataType
@@ -22,7 +22,7 @@ import IJulia: InlineIOContext
 
     Base.show(InlineIOContext(buf), MIME("text/plain"), data)
     @test String(take!(buf)) == "TestDataType: Jupyter: \"foo\""
-    
+
     # test that we can extract a PNG header
     @test png_wh(
         "iVBORw0KGgoAAAANSUhEUgAAAAUAAAAMCAYAAACqYHctAAAAE0lEQVR42mNk+P+/ngENMI4MQQCgfR3py/"