code: public List<Sample> getSamples(String studyId) {
          VariantStudyMetadata variantStudyMetadata = getVariantStudyMetadata(studyId);
          if (variantStudyMetadata == null) {
              logger.error("Study not found. Check your study ID: '{}'", studyId);
              return null;
          }
  
          List<Sample> samples = new ArrayList<>();
          if (variantStudyMetadata.getIndividuals() != null) {
              for (org.opencb.biodata.models.metadata.Individual individual : variantStudyMetadata.getIndividuals()) {
                  for (Sample sample : individual.getSamples()) {
                      if (sample.getAnnotations() == null) {
                          sample.setAnnotations(new HashMap<>());
                      }
                      samples.add(sample);
                  }
              }
          }
          return samples;
      }
docs: Retrieve all samples for a given study (from its study ID).
  
  @param studyId   Study ID
  @return          Sample list