code: public void deletePipelineScheduleVariable(Object projectIdOrPath, Integer pipelineScheduleId, String key) throws GitLabApiException {
          Response.Status expectedStatus = (isApiVersion(GitLabApi.ApiVersion.V3) ? Response.Status.OK : Response.Status.NO_CONTENT);
          delete(expectedStatus, null, "projects", getProjectIdOrPath(projectIdOrPath),
                  "pipeline_schedules", pipelineScheduleId, "variables", key);
      }
docs: Deletes a pipeline schedule variable.
  
  <pre><code>DELETE /projects/:id/pipeline_schedules/:pipeline_schedule_id/variables/:key</code></pre>
  
  @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
  @param pipelineScheduleId the pipeline schedule ID
  @param key the key of an existing pipeline schedule variable
  @throws GitLabApiException if any exception occurs