code: public String buildWhere(Set<Map.Entry<String, Object>> fields) {
  		StringBuilder selection = new StringBuilder();
  		for (Map.Entry<String, Object> field : fields) {
  			if (selection.length() > 0) {
  				selection.append(" AND ");
  			}
  			selection.append(buildWhere(field.getKey(), field.getValue()));
  		}
  		return selection.toString();
  	}
docs: Build where (or selection) statement from the fields
  
  @param fields
  fields
  @return where clause