FileName returns the filename parameter of the [Part]'s Content-Disposition
header. If not empty, the filename is passed through filepath.Base (which is
platform dependent) before being returned.
Returns string
formName
formName(): string
FormName returns the name parameter if p has a Content-Disposition
of type "form-data". Otherwise it returns the empty string.
Returns string
read
read(d): number
Read reads the body of a part, after its headers and before the
next part (if any) begins.
The headers of the body, if any, with the keys canonicalized
in the same fashion that the Go http.Request headers are.
For example, "foo-bar" changes case to "Foo-Bar"
A Part represents a single part in a multipart body.