Try correcting the name to an existing named parameter's name, or defining a named parameter with the name 'sane'. See https://dart.dev/diagnostics/undefined_named_parameter to learn more about this problem.

Try correcting the name to the name of an existing method, or defining a method named 'spawn'. See https://dart.dev/diagnostics/undefined_method to learn more about this problem.

Try correcting the name to the name of an existing method, or defining a method named 'read'. See https://dart.dev/diagnostics/undefined_method to learn more about this problem.

Try correcting the name to the name of an existing method, or defining a method named 'cancel'. See https://dart.dev/diagnostics/undefined_method to learn more about this problem.

Try correcting the name to the name of an existing method, or defining a method named 'close'. See https://dart.dev/diagnostics/undefined_method to learn more about this problem.

Try correcting the name to the name of an existing method, or defining a method named 'exit'. See https://dart.dev/diagnostics/undefined_method to learn more about this problem.

Try correcting the name to the name of an existing method, or defining a method named 'kill'. See https://dart.dev/diagnostics/undefined_method to learn more about this problem.

Try correcting the name to one that is defined, or defining the name. See https://dart.dev/diagnostics/undefined_identifier to learn more about this problem.

Try correcting the name to the name of an existing method, or defining a method named 'cancel'. See https://dart.dev/diagnostics/undefined_method to learn more about this problem.

Try correcting the name to the name of an existing method, or defining a method named 'close'. See https://dart.dev/diagnostics/undefined_method to learn more about this problem.

Try updating this class to match the superclass, or removing the override annotation. See https://dart.dev/diagnostics/override_on_non_overriding_member to learn more about this problem.

Try updating this class to match the superclass, or removing the override annotation. See https://dart.dev/diagnostics/override_on_non_overriding_member to learn more about this problem.

Try updating this class to match the superclass, or removing the override annotation. See https://dart.dev/diagnostics/override_on_non_overriding_member to learn more about this problem.

Try updating this class to match the superclass, or removing the override annotation. See https://dart.dev/diagnostics/override_on_non_overriding_member to learn more about this problem.

Try updating this class to match the superclass, or removing the override annotation. See https://dart.dev/diagnostics/override_on_non_overriding_member to learn more about this problem.

Try updating this class to match the superclass, or removing the override annotation. See https://dart.dev/diagnostics/override_on_non_overriding_member to learn more about this problem.

Try updating this class to match the superclass, or removing the override annotation. See https://dart.dev/diagnostics/override_on_non_overriding_member to learn more about this problem.

Try updating this class to match the superclass, or removing the override annotation. See https://dart.dev/diagnostics/override_on_non_overriding_member to learn more about this problem.

Try removing the import directive. See https://dart.dev/diagnostics/unused_import to learn more about this problem.