code: public static Schema of(Type type) {
      Preconditions.checkArgument(type.isSimpleType(), "Type %s is not a simple type.", type);
      return new Schema(type, null, null, null, null, null, null, null);
    }
docs: Creates a {@link Schema} for the given type. The type given must be a
  {@link Schema.Type#isSimpleType() Simple Type}.
  
  @param type Type of the schema to create.
  @return A {@link Schema} with the given type.