I have this object project.task that has many situations project.task.situation . In project.task.situation model I want to create a sequence so I added this record:

<record id="sequence_project_task_situation_seq" model="ir.sequence">
    <field name="name">Project Task Situation Sequence</field>
    <field name="code">project.task.situation</field>
    <field name="prefix">Situation N°</field>
    <field eval="1" name="number_next"/>
    <field eval="1" name="number_increment"/>
    <field eval="False" name="company_id"/>
</record>

In python code I added this:

name = fields.Char(string='Situation Number', readonly=True)
@api.model
def create(self, vals):
    seq = self.env['ir.sequence'].next_by_code('project.task.situation') or '/'
    vals['name'] = seq
    return super(ProjectTaskSituation, self).create(vals)

what I want is each task has its own situation sequence. For example for task1 I create 2 situations so I have Situation N°1 and Situation N°2 after that I want to create situations for task2 so I'll get Situation N°3 and Situation N°4 . Which is not good cause I want for each task to start count sequence from the start. Is this possible? How is that?