Creates a new attribute statement.
The type of attributes: graph, node, or edge.
The list of attributes.
The list of attributes.
The type of attributes: graph, node, or edge.
Adds an attribute to the attribute list.
The key of the attribute.
The value of the attribute.
This attribute statement, for chaining.
Adds multiple attributes to the attribute list.
The attributes to add.
This attribute statement, for chaining.
Converts the attribute statement to a dot string.
Whether the graph is directed (unused).
The number of spaces to indent.
The dot string of the attribute statement.
An attribute statement, such as
graph [label="Hello"];.