code: function ClientSSLSecurity(key, cert, ca, defaults) {
    if (key) {
      if(Buffer.isBuffer(key)) {
        this.key = key;
      } else if (typeof key === 'string') {
        this.key = fs.readFileSync(key);
      } else {
        throw new Error('key should be a buffer or a string!');
      }
    }
  
    if (cert) {
      if(Buffer.isBuffer(cert)) {
        this.cert = cert;
      } else if (typeof cert === 'string') {
        this.cert = fs.readFileSync(cert);
      } else {
        throw new Error('cert should be a buffer or a string!');
      }
    }
  
    if (ca) {
      if(Buffer.isBuffer(ca) || Array.isArray(ca)) {
        this.ca = ca;
      } else if (typeof ca === 'string') {
        this.ca = fs.readFileSync(ca);
      } else {
        defaults = ca;
        this.ca = null;
      }
    }
  
    this.defaults = {};
    _.merge(this.defaults, defaults);
  
    this.agent = null;
  }
docs: activates SSL for an already existing client
  
  @module ClientSSLSecurity
  @param {Buffer|String}   key
  @param {Buffer|String}   cert
  @param {Buffer|String|Array}   [ca]
  @param {Object}          [defaults]
  @constructor