diff --git a/jenkins.js b/jenkins.js
index 0a0c545..0c9ab17 100644
--- a/jenkins.js
+++ b/jenkins.js
@@ -7,6 +7,7 @@ const fs = require ('fs');
 const child_process = require ('child_process');
 
 const pkg = JSON.parse (fs.readFileSync ('package.json', 'utf-8'));
+
 [
   ,, pkg.version
 ] = process.argv;
diff --git a/lib/Edge.ts b/lib/Edge.ts
index 638b293..3709f04 100644
--- a/lib/Edge.ts
+++ b/lib/Edge.ts
@@ -17,6 +17,7 @@ export class Edge {
   // eslint-disable-next-line @typescript-eslint/naming-convention
   public toString (): string {
     const attributes = [];
+
     if (this.style)
       attributes.push ({ name: 'style', value: this.style.toString () });
     if (this.color)
diff --git a/lib/Element.ts b/lib/Element.ts
index 160c16c..6079683 100644
--- a/lib/Element.ts
+++ b/lib/Element.ts
@@ -14,6 +14,7 @@ export class Element {
 
   public constructor (name: string, parent = '') {
     const regex = /^[a-z_][a-z_0-9]+$/iu;
+
     if (!regex.test (name))
       throw new Error ('invalid name specified');
     this.name = name;
diff --git a/lib/GraphLayouts.ts b/lib/GraphLayouts.ts
index a856eef..29ae2ba 100644
--- a/lib/GraphLayouts.ts
+++ b/lib/GraphLayouts.ts
@@ -1,4 +1,10 @@
 export enum GraphLayouts {
-  neato= 'neato',
-  dot= 'dot'
+  neato = 'neato',
+  dot = 'dot',
+  circo = 'circo',
+  fdp = 'fdp',
+  sfdp = 'sfdp',
+  osage = 'osage',
+  twopi = 'twopi',
+  patchwork = 'patchwork'
 }
diff --git a/lib/Node.ts b/lib/Node.ts
index 815712e..0f72262 100644
--- a/lib/Node.ts
+++ b/lib/Node.ts
@@ -20,6 +20,7 @@ export class Node extends Element {
 
     const mapped_columns = this.table_contents
       .map ((val) => `<td>${val.join ('</td><td>')}</td>`);
+
     return `<table>\n  <tr>${
       mapped_columns.join ('</tr>\n  <tr>')
     }</tr>\n</table>`;
@@ -28,6 +29,7 @@ export class Node extends Element {
   // eslint-disable-next-line @typescript-eslint/naming-convention
   public toString (): string {
     const attributes = [];
+
     if (this.label || this.is_table) {
       attributes.push ({
         name:  'label',
@@ -51,6 +53,7 @@ export class Node extends Element {
           '"',
           '"'
         ];
+
       return `${v.name}=${d[0]}${v.value}${d[1]}`;
     })
       .join (', ');
diff --git a/test/Color.ts b/test/Color.ts
index 5a77f1f..75b020a 100644
--- a/test/Color.ts
+++ b/test/Color.ts
@@ -4,6 +4,7 @@ import { Color } from '../lib';
 test ('serialize', (t) => {
   const wh = Color.white;
   const tr = Color.transparent;
+
   t.is (wh.toString (), '#ffffff');
   t.is (tr.toString (), '#00000000');
 });
diff --git a/test/Edge.ts b/test/Edge.ts
index 0daa371..faa2610 100644
--- a/test/Edge.ts
+++ b/test/Edge.ts
@@ -3,16 +3,20 @@ import { Edge, Color, EdgeStyles } from '../lib';
 
 test ('serialize', (t) => {
   const e = new Edge ('foo', 'bar', false);
+
   e.color = Color.white;
   e.style = EdgeStyles.dashed;
   const serialized = e.toString ();
+
   t.is (serialized, 'foo -- bar [style="dashed",color="#ffffff"]');
 });
 
 test ('serialize directional', (t) => {
   const e = new Edge ('foo', 'bar', true);
+
   e.color = Color.white;
   e.style = EdgeStyles.dashed;
   const serialized = e.toString ();
+
   t.is (serialized, 'foo -> bar [style="dashed",color="#ffffff"]');
 });
diff --git a/test/Node.ts b/test/Node.ts
index 829cace..aaca102 100644
--- a/test/Node.ts
+++ b/test/Node.ts
@@ -11,16 +11,19 @@ const serialized_table = `bar_foo [label=<<table>
 
 test ('serialize simple', (t) => {
   const g = new Node ('foo', 'bar', 'baz');
+
   g.color = Color.green;
   g.style = NodeStyles.dashed;
 
   const serialized = g.toString ();
+
   t.is (g.full_name, 'bar_foo');
   t.is (serialized, serialized_simple);
 });
 
 test ('serialize table', (t) => {
   const g = new Node ('foo', 'bar', 'baz');
+
   g.color = Color.green;
   g.style = NodeStyles.invisible;
 
@@ -44,6 +47,7 @@ test ('serialize table', (t) => {
   g.is_table = true;
 
   const serialized = g.toString ();
+
   t.is (g.full_name, 'bar_foo');
   t.is (serialized, serialized_table);
 });
@@ -51,6 +55,7 @@ test ('serialize table', (t) => {
 test ('adhere to naming convention', (t) => {
   t.throws (() => {
     const n = new Node ('invalid.name', 'parent');
+
     return n.toString ();
   }, { message: 'invalid name specified' });
 });