Emulating JQL "in" functionality in Nunjucks?

[Olap]

In JQL, I can write customer in ("customer A", "Customer B", "Customer C")

What would be the equivalent in Nunjucks? How can I create a condition to emulate that? 

Something like {{ issue.fields.issuetype.customer <in> ("customer A", "Customer B", "Customer C") }}

Any idea?

[Olap]

{% set trigger = false %}
{% for item in[{ title: "cust A"}, { title: "cust B"}, { title: "cust C"},{ title: "cust D"}] %}
{% if issue.fields["Customer"] == item.title %}
{% set trigger = true %}
{% endif %}
{% endfor %}
{{ trigger }}