Swagger json issue with POST in php client generated

gistfile1.txt

{
  "swagger": "2.0",
  "info": {
    "title": "[%api-title%]",
    "description": "[%api-description%]",
    "version": "1.0.0"
  },
  "host": "my.website.com",
  "schemes": [
    "http"
  ],
  "produces": [
    "application/json"
  ],
  "paths": {
    "/v{version}/apicheck": {
      "parameters": [
        {"$ref": "#/parameters/apiVersion"}
      ],
      "post": {
        "summary": "apicheck-apicheckpost-summary",
        "description": "[%apicheck-apicheckpost-description%]",
        "parameters": [
          {"$ref": "#/parameters/apicheckTestParameter"}
        ],
        "tags": ["apicheck"],
        "responses": {
          "200": {
            "description": "[%apicheck-apicheckpost-response-200-description%]",
            "schema": {
              "$ref": "#/definitions/apicheckPost"
            }
          }
        }
      }
    }    
  },
  "parameters": {
    "apicheckTestParameter": {
      "name": "test_param",
      "in": "formData",
      "description": "[%parameter-apicheck-test-param-description%]",
      "required": false,
      "type": "string"
    }
  },

  "definitions": {    
    "apicheckPost": {
      "type": "object",
      "properties": {
        "body": {
          "type": "object",
          "description": "[%response-header-body%]",
          "properties": {
            "test_param": {
              "type": "string",
              "description": "[%response-apicheck-test-parameter%]"
            }
          }
        }
      }
    }   
  }
}