code: public static Field field(String name,ArrowType arrowType) {
          return new Field(name,FieldType.nullable(arrowType), new ArrayList<Field>());
      }
docs: Shortcut method for returning a field
  given an arrow type and name
  with no sub fields
  @param name the name of the field
  @param arrowType the arrow type of the field
  @return the resulting field