BUG: Set ivar to appropriate value when condition is met

Set the appropriate value to the `itk::OnePlusOneEvolutionaryOptimizer`
`m_Initialized` ivar when the condition described in the documentation
for its purpose is fulfilled.

The variable was initialized to `false` in the constructor and its value
was not being changed anywhere else, and the variable is not meant to be
changed through a setter method.

Modules/Numerics/Optimizers/src/itkOnePlusOneEvolutionaryOptimizer.cxx

@@ -73,6 +73,8 @@ OnePlusOneEvolutionaryOptimizer::Initialize(double initialRadius, double grow, d
   {
     m_ShrinkFactor = shrink;
   }
+
+  m_Initialized = true;
 }
 
 void

Modules/Numerics/Optimizers/test/itkOnePlusOneEvolutionaryOptimizerTest.cxx

@@ -20,6 +20,7 @@
 #include "itkNormalVariateGenerator.h"
 #include "itkCommand.h"
 #include "itkMath.h"
+#include "itkTestingMacros.h"
 
 namespace itk
 {
@@ -152,6 +153,8 @@ itkOnePlusOneEvolutionaryOptimizerTest(int, char *[])
   // Declaration of an itkOptimizer
   auto itkOptimizer = OptimizerType::New();
 
+  ITK_TEST_EXPECT_TRUE(!itkOptimizer->GetInitialized());
+
   itk::OnePlusOneCommandIterationUpdate::Pointer observer = itk::OnePlusOneCommandIterationUpdate::New();
   itkOptimizer->AddObserver(itk::IterationEvent(), observer);
 
@@ -178,6 +181,8 @@ itkOnePlusOneEvolutionaryOptimizerTest(int, char *[])
   itkOptimizer->SetMaximumIteration(8000);
 
 
+  ITK_TEST_EXPECT_TRUE(itkOptimizer->GetInitialized());
+
   using GeneratorType = itk::Statistics::NormalVariateGenerator;
   auto generator = GeneratorType::New();
   itkOptimizer->SetNormalVariateGenerator(generator);