code: public <V> void setColumnValue(T instance, String columnName, V value) {
          Field field = fields.get(columnName);
          if (field == null) {
              throw new IllegalArgumentException("Column not found: "
                      + columnName);
          }
          try {
              field.set(instance, value);
          } catch (IllegalAccessException e) {
              throw new RuntimeException(e); // should never get here
          }
      }
docs: Set the value for the given column for the given instance
  
  @param instance
  the instance
  @param columnName
  name of the column (must match a corresponding annotated field
  in the instance's class)
  @param value
  The value (must match the actual native type in the instance's
  class)