fix: catching exception in TransformHelper

source/RobotAPI/libraries/armem_robot_state/common/localization/TransformHelper.cpp

 #include "TransformHelper.h"
+#include <optional>
 #include <string>
 
 #include <SimoxUtility/algorithm/get_map_keys_values.h>
@@ -48,12 +49,23 @@ namespace armarx::armem::common::robot_state::localization
         const std::vector<Eigen::Affine3f> transforms = _obtainTransforms(
                     localizationCoreSegment, tfChain, query.header.agent, query.header.timestamp);
 
-        const armem::Time sanitizedTimestamp = _obtainTimestamp(localizationCoreSegment, query.header.timestamp);
+        const std::optional<armem::Time> sanitizedTimestamp = _obtainTimestamp(localizationCoreSegment, query.header.timestamp);
+
+        if(not sanitizedTimestamp.has_value())
+        {
+            return {.transform    = {.header = query.header},
+                    .status       = TransformResult::Status::Error,
+                    .errorMessage = "Error: Issue with timestamp"};
+        }
+
+
         auto header = query.header;
 
+        ARMARX_CHECK(sanitizedTimestamp.has_value());
+
         // ARMARX_INFO << header.timestamp << "vs" << sanitizedTimestamp;
 
-        header.timestamp = sanitizedTimestamp;
+        header.timestamp = sanitizedTimestamp.value();
                 
         if (transforms.empty())
         {
@@ -178,27 +190,43 @@ namespace armarx::armem::common::robot_state::localization
     }
 
     template <class ...Args>
-    armarx::core::time::DateTime
+    std::optional<armarx::core::time::DateTime>
     TransformHelper::_obtainTimestamp(const armem::base::CoreSegmentBase<Args...>& localizationCoreSegment, const armem::Time& timestamp)
     {
         
         // first we check which the newest timestamp is
-        int64_t timeSinceEpochUs = 0;
+        std::optional<int64_t> timeSinceEpochUs = std::nullopt;
 
         localizationCoreSegment.forEachEntity([&timeSinceEpochUs, &timestamp](const auto& entity){
             auto snapshot = entity.findLatestSnapshotBeforeOrAt(timestamp);
+
+            if(snapshot == nullptr)
+            {
+                return;
+            }
+
+            if(not snapshot->hasInstance(0))
+            {
+                return;
+            }
+
             const armem::wm::EntityInstance& item = snapshot->getInstance(0);
             const auto tf = _convertEntityToTransform(item);
             
             const auto& dataTs = tf.header.timestamp;
 
-            timeSinceEpochUs = std::max(timeSinceEpochUs, dataTs.toMicroSecondsSinceEpoch());
+            timeSinceEpochUs = std::max(timeSinceEpochUs.value_or(0), dataTs.toMicroSecondsSinceEpoch());
         });
 
+        if(not timeSinceEpochUs.has_value())
+        {
+            return std::nullopt;
+        }
+
         // then we ensure that the timestamp is not more recent than the query timestamp
-        timeSinceEpochUs = std::min(timeSinceEpochUs, timestamp.toMicroSecondsSinceEpoch());
+        timeSinceEpochUs = std::min(timeSinceEpochUs.value(), timestamp.toMicroSecondsSinceEpoch());
 
-        return armarx::core::time::DateTime(armarx::core::time::Duration::MicroSeconds(timeSinceEpochUs));
+        return armarx::core::time::DateTime(armarx::core::time::Duration::MicroSeconds(timeSinceEpochUs.value()));
     }
 
 

source/RobotAPI/libraries/armem_robot_state/common/localization/TransformHelper.h

@@ -113,7 +113,7 @@ namespace armarx::armem::common::robot_state::localization
 
         template <class ...Args>
         static
-        armarx::core::time::DateTime
+        std::optional<armarx::core::time::DateTime>
         _obtainTimestamp(const armem::base::CoreSegmentBase<Args...>& localizationCoreSegment, const armem::Time& timestamp);
 
         static