#45 Fix: support query parameters without value

[codecov[bot]]

Codecov Report

Patch coverage: 100.00% and project coverage change: -0.01 :warning:

Comparison is base (11712bf) 92.95% compared to head (b322aed) 92.94%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #49 +/- ## ============================================ - Coverage 92.95% 92.94% -0.01% + Complexity 1899 1895 -4 ============================================ Files 124 124 Lines 4227 4223 -4 Branches 602 599 -3 ============================================ - Hits 3929 3925 -4 - Misses 162 163 +1 + Partials 136 135 -1 ``` | [Impacted Files](https://codecov.io/gh/open-coap/java-coap/pull/49?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-coap) | Coverage Δ | | |---|---|---| | [.../java/com/mbed/coap/packet/BasicHeaderOptions.java](https://codecov.io/gh/open-coap/java-coap/pull/49?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-coap#diff-Y29hcC1jb3JlL3NyYy9tYWluL2phdmEvY29tL21iZWQvY29hcC9wYWNrZXQvQmFzaWNIZWFkZXJPcHRpb25zLmphdmE=) | `95.07% <ø> (+0.50%)` | :arrow_up: | | [...va/com/mbed/coap/packet/DataConvertingUtility.java](https://codecov.io/gh/open-coap/java-coap/pull/49?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-coap#diff-Y29hcC1jb3JlL3NyYy9tYWluL2phdmEvY29tL21iZWQvY29hcC9wYWNrZXQvRGF0YUNvbnZlcnRpbmdVdGlsaXR5LmphdmE=) | `97.77% <100.00%> (+0.05%)` | :arrow_up: | ... and [1 file with indirect coverage changes](https://codecov.io/gh/open-coap/java-coap/pull/49/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-coap) Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-coap). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-coap)

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