title: What are the mandatory options for loading Excel file?
body: <p>I have loaded an excel file from S3 using the below syntax, but I am wondering about the options that need to be set here. </p>
  
  <p>Why is it mandatory to set all the below options for loading excel file? None of these options are mandatory for loading other file types like csv,del,json,avro etc.</p>
  
  <pre><code>val data = sqlContext.read.
  format("com.crealytics.spark.excel").
  option("location", s3path).
  option("useHeader", "true").
  option("treatEmptyValuesAsNulls", "true").
  option("inferSchema","true").
  option("addColorColumns", "true").
  load(path)
  </code></pre>
  
  <p>I get the below error if any of the above options(except location) are not set:</p>
  
  <pre><code>sqlContext.read.format("com.crealytics.spark.excel").option("location", s3path).load(s3path)
  </code></pre>
  
  <p>Error message : </p>
  
  <pre><code>Name: java.lang.IllegalArgumentException
  Message: Parameter "useHeader" is missing in options.
  StackTrace:   at com.crealytics.spark.excel.DefaultSource.checkParameter(DefaultSource.scala:37)
            at com.crealytics.spark.excel.DefaultSource.createRelation(DefaultSource.scala:19)
            at com.crealytics.spark.excel.DefaultSource.createRelation(DefaultSource.scala:7)
            at org.apache.spark.sql.execution.datasources.DataSource.resolveRelation(DataSource.scala:345)
            at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:149)
            at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:132)
            at $anonfun$1.apply(&lt;console&gt;:47)
            at $anonfun$1.apply(&lt;console&gt;:47)
            at time(&lt;console&gt;:36)
  </code></pre>