Notice: Undefined index: sum

[pluk77]

For some reason, occasionally one of the histograms throws a PHP notice when displaying the metrics.

Not 100% sure this is a bug in your bundle, or the metrics bundle that wraps your bundle in Symfony.

The historgram in question:

pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="0.005"} 0 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="0.01"} 0 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="0.025"} 0 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="0.05"} 0 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="0.075"} 0 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="0.1"} 0 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="0.25"} 2 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="0.5"} 4 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="0.75"} 4 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="1"} 4 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="2.5"} 4 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="5"} 4 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="7.5"} 4 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="10"} 4 pas_request_durations_histogram_seconds_bucket{action="POST-saml_acs",le="+Inf"} 4

storage: APCu promphp/prometheus_client_php: v2.6.2 artprima/prometheus-metrics-bundle: v1.14.0

I can not replicate why this happened, just that it happened and resolves itself. However, the fix is small and easy, as per my PR.