class ActiveRecord::FixtureSet::ModelMetadata

def has_primary_key_column?
  @has_primary_key_column ||= primary_key_name &&
    @model_class.columns.any? { |col| col.name == primary_key_name }
end

def inheritance_column_name
  @inheritance_column_name ||= @model_class && @model_class.inheritance_column
end

def initialize(model_class)
  @model_class = model_class
end

def primary_key_name
  @primary_key_name ||= @model_class && @model_class.primary_key
end

def primary_key_type
  @primary_key_type ||= @model_class && @model_class.type_for_attribute(@model_class.primary_key).type
end

def timestamp_column_names
  @model_class.all_timestamp_attributes_in_model
end