APEX SOQL equal and in both work

equalIn.java

// Maybe everyone already knew this, but equal and in both work for collections
// in APEX.
Account_Team__c[] ats = [select Id, Account__c from Account_Team__c limit 3];
Set<Id> accId = new Set<Id>();
for (Account_Team__c at : ats) {
    accId.add(at.Account__c);
}
Account_Team__c[] accTeams = [
  SELECT Account__c, Role__c, User__c
  FROM Account_Team__c
  WHERE Account__c = :accId // THIS WORKS
];
System.debug(accTeams);
accTeams = [
  SELECT Account__c, Role__c, User__c
  FROM Account_Team__c
  WHERE Account__c in :accId // of course this works
];
System.debug(accTeams);