code: private List<IndexExpression> filteredExpressions(List<IndexExpression> clause) {
          List<IndexExpression> filteredExpressions = new ArrayList<>(clause.size());
          for (IndexExpression ie : clause) {
              ByteBuffer columnName = ie.column;
              if (!indexedColumnName.equals(columnName)) {
                  filteredExpressions.add(ie);
              }
          }
          return filteredExpressions;
      }
docs: Returns the {@link IndexExpression} not relative to this index.
  
  @param clause A list of {@link IndexExpression}s.
  @return The {@link IndexExpression} not relative to this index.