I've modified sale order line to include another field. I'm trying to access the value of that field in another model. Below is a simplified version of my code.
The error that I am getting is: 

KeyError: 'state_id'


class SaleOrderLine(models.Model):
    _inherit = 'sale.order.line'
    state_id = fields.Many2one('res.country.state', string='Jurisdiction')
    compliance_workflow_id = fields.Many2one('compliance.workflow', string='Workflow')

class  ComplianceWorkflow(models.Model):
    _name = 'compliance.workflow'
    _description = 'Compliance workflow'

    order_id = fields.Many2one('sale.order', string='Order')
    order_line_id = fields.Many2one('sale.order.line', string='Order line')
    state_id = fields.Many2one('res.country.state', related='order_line_id.state_id', string="Jurisdiction")