diff --git a/project.clj b/project.clj
index 0fad771..22c64df 100644
--- a/project.clj
+++ b/project.clj
@@ -7,7 +7,8 @@
   :dependencies [[org.clojure/clojure "1.10.1"]
                  [org.testcontainers/testcontainers "1.14.3"]]
   :plugins [[metosin/bat-test "0.4.4"]]
-  :bat-test {:report [:pretty {:type :junit 
+  :bat-test {:report [:pretty {:type :junit
                                :output-to "target/junit.xml"}]}
+  :profiles {:dev {:dependencies [[org.testcontainers/postgresql "1.14.3"]]}}
   :target-path "target/%s")
 
diff --git a/src/clj_test_containers/core.clj b/src/clj_test_containers/core.clj
index bda7988..763f4ae 100644
--- a/src/clj_test_containers/core.clj
+++ b/src/clj_test_containers/core.clj
@@ -12,23 +12,27 @@
     BindMode/READ_WRITE
     BindMode/READ_ONLY))
 
-(defn create
+(defn init
   "Sets the properties for a testcontainer instance"
-  [{:keys [image-name exposed-ports env-vars command]}]
-  (let [container (GenericContainer. image-name)]
-    (.setExposedPorts container (map int exposed-ports))
+  [{:keys [container exposed-ports env-vars command]}]
+  (.setExposedPorts container (map int exposed-ports))
 
-    (if (some? env-vars)
-      (doseq [pair env-vars]
-        (.addEnv container (first pair) (second pair))))
+  (run! (fn [[k v]] (.addEnv container k v)) env-vars)
 
-    (if (some? command)
-      (.setCommand container command))
+  (when command
+    (.setCommand container command))
 
-    {:container container
-     :exposed-ports (.getExposedPorts container)
-     :env-vars (.getEnvMap container)
-     :host (.getHost container)}))
+  {:container container
+   :exposed-ports (vec (.getExposedPorts container))
+   :env-vars (into {} (.getEnvMap container))
+   :host (.getHost container)})
+
+(defn create
+  "Creates a generic testcontainer and sets its properties"
+  [{:keys [image-name] :as options}]
+  (->> (GenericContainer. image-name)
+       (assoc options :container)
+       init))
 
 (defn create-from-docker-file
   [{:keys [exposed-ports env-vars command docker-file]
diff --git a/test/clj_test_containers/core_test.clj b/test/clj_test_containers/core_test.clj
index c78067e..973d15f 100644
--- a/test/clj_test_containers/core_test.clj
+++ b/test/clj_test_containers/core_test.clj
@@ -1,9 +1,12 @@
 (ns clj-test-containers.core-test
   (:require [clojure.test :refer :all]
-            [clj-test-containers.core :refer :all]))
+            [clj-test-containers.core :refer :all])
+  (:import [org.testcontainers.containers
+            PostgreSQLContainer]))
+
+(deftest create-test
+  (testing "Testing basic testcontainer generic image initialisation"
 
-(deftest init-test
-  (testing "Testing basic testcontainer generic image initialization"
     (let [container (create {:image-name "postgres:12.2"
                              :exposed-ports [5432] 
                              :env-vars {"POSTGRES_PASSWORD" "pw"}})
@@ -30,12 +33,22 @@
 
   (testing "Executing a command in the running Docker container"
     (let [container (create {:image-name "postgres:12.2"
-                             :exposed-ports [5432] 
+                             :exposed-ports [5432]
                              :env-vars {"POSTGRES_PASSWORD" "pw"}})
           initialized-container (start! container)
           result (execute-command! initialized-container ["whoami"])
           stopped-container (stop! container)]
       (is (= 0 (:exit-code result)))
+      (is (= "root\n" (:stdout result)))))
+
+  (testing "Executing a command in the running Docker container with a custom container"
+    (let [container (init {:container (PostgreSQLContainer. "postgres:12.2")
+                           :exposed-ports [5432]
+                           :env-vars {"POSTGRES_PASSWORD" "pw"}})
+          initialized-container (start! container)
+          result (execute-command! initialized-container ["whoami"])
+          stopped-container (stop! container)]
+      (is (= 0 (:exit-code result)))
       (is (= "root\n" (:stdout result))))))
 
 (deftest init-volume-test