It might be the last API that does not implement $segment support. It should!
Reported in forum post.
Pull request: https://github.com/piwik/piwik/pull/121
In 7778531b481c16a23f8aadf26aac48130de63bd1: Merge pull request #121 from piwikpro-team/2781-segmentation-on-Goals.getItems
Fixes #2781 Add support for segmentation on Goals.getItems* API. Kuddos for the nice pull request and tests!
In 44d9bcef32438c8fe0c66d7aa4217bf27091dc2b: Refs #2781 PR #121 Modifying tests fixtures to generate visits from two countries so that it's clear that the Segmenting on the country selects only that country.
In 93d5d1f7df2046bd60685d4e9792e8c9e48abd00: Refs #2781 PR #121 Fixing regression the "distinct idvisit" was removed in the PR