Coffin template showing duplicate keys are not created in coffin compile

rds-test.coffin

## Cloudformation Description Resource
@Description "A simple MySQL RDS test stack"

@Param.String 'home1',           Default: '192.168.0.1/32'
@Param.String 'home2',           Default: '192.168.0.2/32'


## Expected: This SecurityGroup should have two entries with IP addresses and two entries with EC2 Securitygroup names within DBSecurityGroupIngress.
## Acctual Result: Only the last item if the duplicate key is in the compiled JSON.
@AWS.RDS.DBSecurityGroup "ec2instances",
  GroupDescription: "We should see 2 CIDRP and 2 EC2SecurityGroupName entries here."
  DBSecurityGroupIngress: 
    CIDRIP: "10.10.10.10/32"
    CIDRIP: "10.11.11.11/32"
    EC2SecurityGroupName: "sampleGroup1"
    EC2SecurityGroupName: "sampleGroup2"

## We can get around this by creating the array ahead of time. However, I must build them in JSON directly. 2 styles presented.
rdsOfficesIngress = [
                 { "CIDRIP": "10.12.12.12/32" },
                 { "CIDRIP": "10.12.12.12/32" },
                 { "EC2SecurityGroupName": "sampleGroup3" },
                 { "EC2SecurityGroupName": "sampleGroup4" }
]

homesParamsIngress = [
                 { "CIDRIP": @Params.home1 },
                 { "CIDRIP": @Params.home2 }
]

## Create the DB group just passing in the pre-built array.
@AWS.RDS.DBSecurityGroup "offices",
  GroupDescription: "Security Group for offices to RDS"
  DBSecurityGroupIngress: rdsOfficesIngress
  
@AWS.RDS.DBSecurityGroup "homes",
  GroupDescription: "Security Group for homes to RDS"
  DBSecurityGroupIngress: homesParamsIngress

## This will susccsfully create a single RDS instances with 2 Security Groups.
@AWS.RDS.DBInstance 'testDB',
  Engine: 'MySQL'
  DBName: 'testDB'
  Port: '3306'
  AllocatedStorage: '5'
  MasterUsername: 'masterUsername'
  MasterUserPassword: 'masterPassword'
  DBInstanceClass: 'db.m1.small'
  DBSecurityGroups: [
    @Resources.ec2instances
    @Resources.offices
  ]

## An Example of where two key/value pairs with the same key would cause confusion. Only udp is in the output on the duplicate IpProtocol.
@AWS.EC2.SecurityGroup 'LoadBalancerSecurityGroup',
  GroupDescription: 'security group to allow the load balancer to talk to the service instance'
  SecurityGroupIngress: [
    IpProtocol: 'tcp'
    IpProtocol: 'udp'
    FromPort:   '80'
    ToPort:     '80'
    SourceSecurityGroupOwnerId: '1234'
    SourceSecurityGroupName:    'Test_Name'
  ]

rds-test.json

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Description": "A simple MySQL RDS test stack",
    "Parameters": {
        "home1": {
            "Default": "192.168.0.1/32",
            "Type": "String"
        },
        "home2": {
            "Default": "192.168.0.2/32",
            "Type": "String"
        }
    },
    "Resources": {
        "ec2instances": {
            "Type": "AWS::RDS::DBSecurityGroup",
            "Properties": {
                "GroupDescription": "We should see 2 CIDRP and 2 EC2SecurityGroupName entries here.",
                "DBSecurityGroupIngress": {
                    "CIDRIP": "10.11.11.11/32",
                    "EC2SecurityGroupName": "sampleGroup2"
                }
            }
        },
        "offices": {
            "Type": "AWS::RDS::DBSecurityGroup",
            "Properties": {
                "GroupDescription": "Security Group for offices to RDS",
                "DBSecurityGroupIngress": [
                    {
                        "CIDRIP": "10.12.12.12/32"
                    },
                    {
                        "CIDRIP": "10.12.12.12/32"
                    },
                    {
                        "EC2SecurityGroupName": "sampleGroup3"
                    },
                    {
                        "EC2SecurityGroupName": "sampleGroup4"
                    }
                ]
            }
        },
        "homes": {
            "Type": "AWS::RDS::DBSecurityGroup",
            "Properties": {
                "GroupDescription": "Security Group for homes to RDS",
                "DBSecurityGroupIngress": [
                    {
                        "CIDRIP": {
                            "Ref": "home1"
                        }
                    },
                    {
                        "CIDRIP": {
                            "Ref": "home2"
                        }
                    }
                ]
            }
        },
        "testDB": {
            "Type": "AWS::RDS::DBInstance",
            "Properties": {
                "Engine": "MySQL",
                "DBName": "testDB",
                "Port": "3306",
                "AllocatedStorage": "5",
                "MasterUsername": "masterUsername",
                "MasterUserPassword": "masterPassword",
                "DBInstanceClass": "db.m1.small",
                "DBSecurityGroups": [
                    {
                        "Ref": "ec2instances"
                    },
                    {
                        "Ref": "offices"
                    }
                ]
            }
        },
        "LoadBalancerSecurityGroup": {
            "Type": "AWS::EC2::SecurityGroup",
            "Properties": {
                "GroupDescription": "security group to allow the load balancer to talk to the service instance",
                "SecurityGroupIngress": [
                    {
                        "IpProtocol": "udp",
                        "FromPort": "80",
                        "ToPort": "80",
                        "SourceSecurityGroupOwnerId": "1234",
                        "SourceSecurityGroupName": "Test_Name"
                    }
                ]
            }
        }
    },
    "Outputs": {}
}