can't see local variables

[TheBearF8]

using 2.17.0 but same with 2.14.1
using agent.onStateChange()
I can see the state change and agent.newState but can't see locally defined variables

public isDialingAvailable: Boolean = false;

connect.agent(agent => {
            console.log("AGENT      Sub     ", agent)
            agent.onStateChange(this.handleAgentStateChange);
});

handleAgentStateChange(agent) { 
     console.log("CCP:  AGENT:     State Changed  Triggered  ", agent ,  agent.newState, agent.newState === "Available", this.isDialingAvailable, this.dialPad );   
}

this.isDialingAvailable returns undefined so does this.dialPad
setting this.isDialingAvailable = true;
Then reports StateChange failed

Please help

[TheBearF8]

Change agent.onStateChange(this.handleAgentStateChange) to
agent.onStateChange( (agent) => this.handleAgentStateChange(agent) );

Then you can access local variables and the functions work